I have Tourette's Syndrome and can give advise on it if anyone needs it! (Hopefully, it fits in this thread!) I'm writing this when I a bit tired so hopefully, this isn't too poorly structured but there a fair few misconceptions or overlooked aspects that could be helpful to know if you want to write a character with tics/TS. For some background, I had very occasional tics since I was about seven/eight that I didn't pay much attention to but when I was fifteen they ramped up super severely over the course of a day and my tics have been constant (and very obvious) ever since. I am very lucky that the area I live in has a very strong TS community and so I've been able to meet and talk to many other people with it but it Tourette's can impact people very differently so it should go without saying that a lot of this comes from my own experience.
To be honest I haven't actually seen very many characters in media as a whole with Tourette's or tic disorders in general, which is kind of surprising since it's not a particularly uncommon condition but when you do see them there is a good 90% chance it focuses almost entirely on coprolalia (swearing tics) as either a joke or in a very sensationalist way. I don't find it inherently bad by any means, they are a very unique thing to have to deal with in everyday life but it very much seems to be the focus on to the extent that lots of people assume that is all the condition is, even though it's a pretty rare symptom (I swear if I have to hear one more person joke that they must have Tourette's because of how much they swear...) There are all sorts of other tic 'types' that I wish I saw more of in fiction like Echolalia (repeating the words of others) and physical tics in general.
As for just some quick stuff that I don't see shown or talked about a lot:
Tourette's Syndrome is often comorbid with other conditions such as OCD, ADHD and anxiety disorders, and it isn't uncommon for those conditions to be diagnosed well before the Tourette's is.
It's not that uncommon to tic on topic, so if I see a dog, I might tic about it playing fetch or if I'm having a conversation about someone's birthday I might tic about birthday cake. That said, tics aren't 'what someone is honestly thinking' so if I tic about hating your shoes it doesn't mean I secretly hate your shoes, it's more of a word association thing.
Many of the other people I've talked to and myself are very easily exhausted and struggled to do a regular full day of work or class, which shouldn't be surprising given just how much moving comes with motor tics.
Tics wax and wane, change in number, frequency, type and can increase from fatigue, anxiety, stress, sensory factors or illness.
Suppressing tics is tricky and exhausting. The best way I've heard it described is it's like trying to hold your breath. It takes focus and as hard as you try your brain will eventually take over and force you to, and when you do it will be much more intense.
Some people's tics get less intense/frequent in adulthood but this isn't always the case and they don't really go away completely
It can be painful. Sometimes I will get tics where I hurt myself and as part of it, I will need to feel the sensation of pain before I stop. So if you move a pillow underneath me I will keep going until it hurts again, the only way to stop is just to fully ride it out, which could take minutes or days.
It can be destructive and expensive. Breaking stuff is pretty common and it can honestly pile up, just 2 days ago I broke I nice lamp and dented a wall...
It can be funny. Plenty of the verbal tics I have genuinely make me laugh, to the point I keep a list of some of my favourites. It can be quite fun to hear the random, creative nonsense your brain generates and I know a bunch of people who fully embrace their tics because of it. I'm personally way less comfortable if people don't laugh and some of my tic since laughing lets me know people aren't annoyed by them.
If anyone has any specific questions I am super happy to answer to the best of my ability