That's a super interesting question. I have thought about it but not too much until now.
do you change their clothes?
The main character is a robot from another planet so he is naked for the most part. So are all the animals that come and go.
But there are four kids... I guess I do change them a little but mostly just the colour.
(yes) how often do you do it and why?
Off the top of my head, they all have about two outfits (not counting times when they are in their pajamas or school uniform or something) which I swap about. This has mostly got to do with the fact that the clothes might clash with the background.
I did used to get annoyed when I watched Cartoon Network and they never changed clothes though so maybe this has affected me on some level.
do you find hard to make clothes look fashionable?
I haven't been trying but... Now you mention it, one girl has an over-sized top and leggings and this is all my little students wear.
can you leave a link to your comic?
https://tapas.io/series/Gombik-Comics
Not all of them have made their way from my desktop computer to Tapas yet. I wanted a buffer for when work dumps an intensive course or a pile of paperwork in my lap. Updates are Wednesdays and Sundays.
do you think clothes make the character?
I think the clothes help to differentiate the characters and often tell you a little something about them. Even in a more realistically drawn comic, I'd try to keep either the colour scheme or the clothes themselves the same.