Hi, I'm Nana Ama, and as a PP survivor, I knoe=w the importance of having a good PP supervisor who you connect with. When you're choosing, there are 3 things I think you should look out for:
Does the person have a lot of free time?:
This is an important question because a large part of your personal project is spent discussing things with your supervisor. If this person is never free, and you keep having to postpone meetings and cut out ideas because you're running out of time, even if you do manage to finish, I can guarantee you you won't be very happy with the result. What you need is someone who can make time for you and sit you down when you're going overboard or give you tips when you have no ideas. Of course, it's not a teachers fault if they're busy, but you can't just let yourself suffer just because they have no time to help you.
Does the teacher relate to your subject choice?:
You want the supervisor to be able to actually understand what your project is about. It makes your work even harder if you're discussing the use of a particular chemical equation in your project and the supervisor can't tell if you're right or wrong. And if the supervisor you want is taken, just choose a supervisor with a subject closely related to yours and you'll be fine.
Are they someone you can talk to easily?
You have to communicate with your supervisor regularly, but if you're terrified of them or you just don't like them, you're just making things complicated for yourself. It's hard to talk to some teachers because they just don't listen or they scare you, so in a situation where you are going to be communicating with this person over the course of a year, just go with someone you can speak freely and vibe with. But seriously though, you don't want to have a literal heart-attack before each meeting, because you're nervous (I've been there done that, and it was not fun).
If you can get all three in a supervisor then you're set, and I hope this helps you because I wish I had this information before I started my Personal Project.