I think a lot of people like for it to look somewhat like themselves, but it's not a requierement at all. A fursona can look exactly the way you want it too, as far as I know. :3

i don't know :/ i don't even have a fursona because i can't decide what animal or anything D:

well a fursona can has ur personality and things you liekz, for example uhh...... wellz if your really hyper or well playfull u can express it in the created character , and in a certain way yes kinda looking like how you ish but id say like a 10% or 12% i dont knowsz mah brain is doin many calculations i cant think cus well its just what iveseen so far, so i guess zat a fursona is something related to ur persona and things ud like AND *SIGH* i has no idea wut else c;

All up to yourself.
Either you can have a fursona that shares parts of your look or mentality, or you can have one that's radically different, or something in between.