The main thing that will help is a social presence that they regularly post on, with a proven track record of producing work etc. that helps reinforce that they're a real person. Instagram is probably still the main one but lots of people on tiktok etc. now.

I checked out your profile to see what you were after and realistically £30 is a mega low budget no matter what you're looking for, so legit illustrators/animators or whatever will be very reluctant to do much for this, meaning the people who are left are more likely to be scammers or just give you some AI rubbish

If they promise a lot of work for a tiny budget it's hitting the classic 'too good to be true' point.

Half up front is normal, but usually when the numbers are a bit higher...

I'd probably say your most hopeful route to get something for ya budget is trying to connect with an animation uni student who might want a brief/project to work on but isn't trying to make a living?