Nope, not at all
I just wing it, I suppose?
Now, except those guys from my comic, I have around 20 OCs for 3 other stories. Of course they change with time (90% of them are existing for 15 years after all!), but I would probably call it development in design and my abilities as artist, not change of character per se.
For example, I had a character in one novel, and later I made 2 characters based on her (I have as much originality as CLAMP, duh). Original look for each of those girls is pink hair, green eyes, tanned skin and clothes in black and blue palette. In the beginning I haven't really thought about colours much, since till 2015 I only used black pencil
Now we have 2 girls from two different worlds and different background, both have the same look, but different clothes: one wears blue kimono, another black and white school uniform.
So with the time, I gave a warrior girl in kimono more natural hue of light pink hair, made her a little bit more interesting colour palette to show her affiliation with clans, made her clothes more Japanese looking and just gave her more appropriate look for her background. The other, witch girl stayed with more violet hair and is still wearing black and white now with a bit of violet and is just having more witchy vibes.
Since they only were characters from novels (and not comic), these changes haven't really change anything in terms of description: one still wears blue kimono and the other just became more free in her school clothes choice - and it is also okay for plot, since most students become undisciplined in their clothes after a few month in school. So even if they were both in comics, they will have those changes gradually and more natural. Like, maybe the girl in kimono had her hair dyed and then the dye will wash off ^^