I only wear my heavy armor when entering a dungeon, preparing to battle, etc. You can save ALOT of time running around in regular clothes. Plus if you ever use 3rd person it’s nice to change it up a bit...

My character is normally in his black robe and a novice hood even if battle unless he feels armor is a good idea.

I have a tendency to change into my special set of Fine Clothes every time I enter town, then get boots and useless jewelry to go with it. Makes me feel about as rich as I am on that game.

Most of my characters tend to change out of their armor and into street clothes before they enter a city. They also take off their weapons. They will find a spot outside somewhere to do this where they can't be seen.

Most of my characters also bathe and swim often. And when they do they take their armor/clothes off for that too.

I make my character(s) change out of armor and into normal clothes before entering any city. I also have them change into enchanted clothes that fit what they are doing. Such as, blacksmithing and enchanting - Blacksmith apron, gloves, boots, and hat tht all have fortify blacksmithing/ barter enchants on (where available) and just walking around, normal clothes, hat, gloves, boots with fortify barter where available.

This. Although my characters don't bathe all that often. Sometimes, but not a lot.

Quite often when in a city im wearing street clothes

Depends on the character I'm playing at the time.
My thieves guild character has a whole chest full of clothes and armor just for disguises.
Can't walk around in thieves guild/Nightingale armor and let everyone know who I am now can I? ; )