I wouldn't worry about it. Your so-called 'weird' faces are cute and you should just be yourself.

Trust me, i am the most unphotogenic person on the planet. XD
BUT, what i do, is i tilt the camera slightly up so that my face seems more relaxed. And then, i smile just a little bit, so that i don't look like i'm dying. Lol

So yeah. Haha it works for me, i guess...

...
Idk
I love doing that
But if you don't like it, then maybe you should just try to pose naturally and try not to think too much about the picture
HOPE THIS HELPS
XD

Lol I do the same
I usually try to relax my face and not think about it to much cause when you think the pic always looks weird or fake especially when you smile
Just pose naturally , calm , and don't think to much about it :))
Hope this helps