Im currently roleplaying an argonian who grew up in the orphanage in riften and came of age and got tossed out on the streets.
Some gameplay restrictions im using that have made things a LOT more fun are:
No perks in crafting, and i can i can only use 1 of the three crafting skills.
I cant improve weapons or armor and i cant sell anything i craft.
I cant use any enchanted items or sell any enchanted items (i went with smithing, if i went with enchanting id allow a self made enchanted neck and ring).
I can only use armor or weapons that i crafted myself or bought from a store (with no smithing perks this makes the good gear hard to come by).
I cant sell weapons or armor (rings and necks are ok though) to stores.
I picked 5 skills beforehand and those will be the only ones i put perks into. This helps me avoid my desire to grab certain perks that are awesome in skills i rarely ever use.
This makes gold MUCH harder to come by and MUCH harder to hold on to. It also makes treasure (like gems and fancy jewelry) feel a lot more like treasure since those are a huge part of my income. It makes playing as a thief feel rewarding since things are worth stealing since gold is hard to come by. It makes combat more challenging. Im really enjoying it a lot.
Its all about what you find fun though, this works for me but might not for you. For more ideas check out this: http://www.gamesas.com/topic/1458747-ridiculous-roleplaying-rules-2/ and pick out ones you think would be fun.