I have two characters but i have rules just for Veronica Volturi:

1- Veronica never touches in a Battle Axe, Maces, WarHammers or War Axes ("That's dirty weapons")
2- Bows are indispensable everytime! ("An arrow stuck in the heart")
3- Claymores for big Monsters! ("Deeper Cut")
4- Dagger for assassination! ("Dagger, the weapon of Death")
5- Longswords for a big group of monsters! ("Cutting everything in sight")
6- Destruction Magic is indispensable! ("Fire, Frost, Lightning")
7- Stealing if necesary ("Like a Chamaleon")
8- Always using Light Armor! ("For a better locomotion")
9- Heavy Armor for Important Quests ("Better safe than sorry")
10- Never trust in a Dremora! ('They are Dirty")

Thats Veronica's Rules!

My current character is a female bosmer that goes naked everywhere. She doesn't even wear rings/amulets or Bound Armor. She relies mainly on marksman, conjuration, and illusion to stay out of harm's way.

My character has the following limitations...

A. He requires sleep. This is induced by a mod. He takes attribute hits when he has gone too long without sleep as a result of the mod. Her carries a bedroll, so finding a bed is no problem. But he will always pay for a bed or use a faction bed when he can.

B. He requires food. This is induced by a mod. His stomach starts to growl and he takes attribute hits when he is hungry. He will always have to carry food with him and/or hunt it while out in the wilds. Everyone knows there are plenty of deer, crabs, and (yeech) rats to hunt and eat.

C. He will not use Conjuration spells or scrolls. This is self-induced role play. In his back story, his father was killed by Conjurors so he refuses to use conjuring magic (not even the "Ancestor Ghost" ability he was born with).

D. He does not "fast travel". I have a mod that brings long distance travel Morrowind style with teleportation portals in Mage Guild Halls and overland travel "strider-style a-la-Morrowind" with riders available at the stables just outside the city walls of all cities. Otherwise, all travel is on foot. He won't be bothered with a horse.

E. He will never kill for the sake of killing. All killing has a purpose. Either to kill a foe that would kill him on sight anyway, or hunting for food.

F. He will join the Mage's Guild only for the purpose of gaining access to The Arcane University, so that he can enchant items. After that, he will have nothing at all to do with Guild politics or purposes.

G. He has helped Baurus and Jauffre to the point of making sure Martin is safe, but he has other things to take care of before he will consider doing anything further to stem the Oblivion crisis.

H. After getting a room in a city, he will change into civilian clothes rather than wear his armor around town.

I. Lastly, when he kills Conjurors, he strips them completely and turns them face down. He keeps the robes as trophies stacked on shelves in his house (another mod that provides a house near Pell's Gate). He also collects Goblin Totems.

I have two rules of thumb, one is not to make potions. I only loot them to sell (although I do save a invisibility/cure disease if I find them or use one to heal if I looted one and I'm in big trouble).
I try to sleep in a bed as often as possible and try to avoid resting unless I can find one.

I don't really keep any strict rules. I see this as a movie with my character being the lead person. If I fast travel, it's because nothing interesting happened on the journey. If I run all the way it's because I want some nice nature shots, and maybe some random encounters. Or just explore and lead up to the next interesting scene with a nice intro.

My character is at heart a good person, but she lives in a tough world where only the strongest survive. Sometimes she has to do things she doesn't like, like steal and maybe even kill people, in order to make it herself. She usually argues that there was a good reason for doing so, and if there's not, then she'll make one up to make herself feel better. Otherwise it would be like watching a Danielle Steele movie; all bliss and nothing remotely interesting happening (and you didn't even get laid that night cause your girlfriend is a sobbing mess). I certainly won't put restrictions on myself which prevent me from exploring all aspects of the game and doing all quest lines. She sees the Thieves Guild as a bunch of poor people who are doing the one thing they can do to stay alive: Steal from those more fortunate, and she has very little scruples being part of that as a lot of those people are her friends and neighbors from when she lived on the Waterfront. And nobody gets hurt. The DB, on the other hand, she does have some concerns about. Fortunately, so far, all the people she has killed were child molesters, killers and generally bad people, so it's ok, but she won't go all the way on this quest line.

I do dress according to the weather, though. I always have my cloak with me and some pants and a jacket of sorts if it starts raining or I'm going to the mountains. I also try to carry as little crap around as possible. Only a handful of scrolls, no books, only the keys I'm currently expecting to use, and only about 10-20 potions. Only 'unrealistic' thing is that I always carry my heavy armor around in a bag in case things get hairy. I also only have one melee weapon and one bow and about 40 arrows (2 quivers).

Other than that, whatever makes the game more fun to play, really

Only fast travel between cities and at a price (to simulate transportation)
and a new thing I've been doing is trying to keep track of what soul is in a soul gem (by only carrying 1 or 2) and only using it for an enchantment that fits the soul. I don't think this is how it would work at all in lore, but it adds a fun spin. Would be a lot easier with the MW system of saying what soul is in what gem.

My character is a raw vegan! Just like her creator

I never steal, only attack if provoked, and get a good sleep every night.

No rules on current character, just a mini mod on the wrist irons enchanted with silence on self and a script who disallow fast travel and making them impossible to remove.
Has not figured out a quest or condition to remove them.

That is cool about the wrist irons. I always RP that they magically prevent spell casting and therefore do a good job of keeping mages under control in prison. During the Tutorial, when Baurus says, "Looks like this is your lucky day," that is when he digs out a key and unlocks them for my characters. All just RP, but fun nonetheless. :goodjob:

Gurkog must have a buzz from alcoholic consumption at all times. If I run out of wine while dungeon crawling I must retreat to the nearest inn and "resupply". Alcohol fueled Orc berserker for the win!

yes I wanted to see how it worked out, lack of fast travel makes the game more slow paced but the silence changes gameplay a lot even if you are not a mage as all sort of shortcuts like charm don't work anymore.
As a bonus, the same script who disables fast travel also heal 10 health once every minute, no help in combat but adds a low level regeneration so I don't have to worry about minor injuries.

Keep the fast travelling down to just main cities stables,
don't carry more than one set of armour at once, more of an encumbarance thing but still
switch too melee when in a close combat situation, none of this sprinting backwards for ages crap

Depending on the character, they'll all have different situations in which they can fast travel. Calacirya fast travels only from cities, but her destination can be anything she wants. Ezra travels between cities and walks the rest of the way. In their Cyrodiil, fast travel is a caravan or Silt Strider ride, or something. Soraya doesn't fast travel at all, because in her world fast travel is a form of magic, which won't be unlocked to her until she's a powerful enough mage - I've set the limit at level 23. After that, she'll be able to fast travel.

Calacirya has maxed out her Blade skill (113), but refuses to touch a sword after she started to feel bad for all the people she had killed with her trusty Ebony Blade. This has roots in me getting bored of one-hit killing everything from liches to mudcrabs. She now uses only archery, and is quickly maxing that out as well (it was +-85 to start with...). She'll move on to only using Destruction next, this time because she seeks challenges.

Ezra uses only a bow, because she's not good enough at anything else for it to be a useful offensive skill. She's actively training her Destruction skill to be a useful weapon skill, but won't hesitate to pick up a sword if her bow fails her.

Soraya is a pure mage and doesn't like killing, but not because she's not capable. She's as pacifistic as a character can be in Cyrodiil, and will prefer a powerful Calm spell over fighting. She will kill if she absolutely has to (to save her own life), but not for any other reasons.

I play dead is dead on all my characters, because otherwise the game is too easy. I do things to make the game harder for me.

In short, personal rules differ from character to character. DiD is probably the only rule that's completely universal to all my characters.

It's not a "rule", but I realised that my first character is ALWAYS a dunmer sorcerer or monk.
And he generally finishes with almost every skills at 100, pretty much invincible by the end of the game. I try to do Everything the game features with this character.

With the other ones, I just put some limitations, like beat the game with out any weapons and not choosing any spell school and unarmed combat as main skills.

Or beat the game without harming anyone (except of courses people you actually have to kill to advance), instead, use "trick spells" like water walk on enemies and flee by swimming deep in the water.

One of the stupidest challenge i made to myself was to only walk backwards during the entire game. I lasted 10 minutes.