My number one piece of advice (in addition to the solid set of points you came up with) would be to write a short character biography.
Don't think too much about it, no one has to see it, it's just for you! Pick something you could relate to (or precisely not that, if want to RP as something unlike yourself). You don't necessarily have to write it up, but it's fun to have a backstory in mind for your character because it gives your character a personal history on which to base his choices (making them all cohere and seem more realistic).
In addition:
- Limit yourself to gear that fits your character bio (in my case, he will most often be seen sporting elven equipment)
- Invest in perk trees that suit your characters back story (in my case: archery, alchemy, sneak, but also for his Nord roots - smithing and swordsmanship)
- Make quest decisions in line with your story (my case, sympathetic towards wood elves, joining Stormcloaks out of desire to be the hero of his true people, a la return of prodigal son)
For instance, my bio idea:
I plan to play a Nord Ranger build. Tall, lean, dark haired and well-travelled, he'll have a windworn but handsome countenance (think Aragorn) and a wariness concealing a warm disposition... His name will be Varik Ulfr, a twist on Old Norse for "Wandering Wolf" (don't correct my etymology, I know it's not exact). His backstory (the reason for his crossing the border into Skyrim at the start of the story) will be:
Born in Cyrodiil to Nord refugees (whose home was ransacked), he was separated as a youth from his parents when they succumbed to a (insert dangerous feline/bear) attack whilst travelling. When his parents didn't return, he left the city walls to look for them, losing his way in the wilderness. Through a natural keen eye, sharp wits and knowledge of wild flora and fauna (passed down from his refugee father, an experienced traveller), he finds himself stumbling through Cyrodiil and finally collapsing some ways into Valenwood. On account of his frail condition and youthful innocence, he is taken under the wing of a mourning Bosmer mother, who shields him from the disapproval of the other Bosmer and raises him in the ways of the Wood elves. On account of his violent reaction upon awakening (at the sight of the alien Bosmer) she names him 'Draugr Rana' - lost wolf (in LOTR elvish). He trains in the bow and learns much of herbal lore, and (being ostracised from the community) spends much of his time wandering the forests, even crossing into other provinces.
Ultimately, as he grows up, becoming taller and more muscular than the Bosmer as well as growing a beard, the community starts to distrust him further and urge his foster mother to make him leave. Understanding the situation and out of sympathy for his saviour, he leaves of his own accord. It is not a very hard decision, he was always ostracised by peers, lacked any chance for love and moreover, having accepted his parents are dead, the Nord seeks to return to his people and reintegrate into his culture; to find his identity.
He treks through the empire and gets caught at the border to Skyrim... and the adventure begins.
Lore-wise this might fall flat with Bosmers taking him in (perhaps they would more plausibly kill him at sight or something, I don't know the relation Nord-Bosmer) but what's important is that its my story and I like it. I can deal with the incongruency, this is my first TES game anyway.)
Now, I just need to get my hands on the game...