I'm currently trying to find my mixed voice, and I regularly do several exercises around my break (slow sirens with and without lip rolls etc), but I still feel completely clueless as to what I'm trying to achieve. I've read up on every site I can find, but I still feel I can't connect the exercises with finding my actual mix. Any tips?
You need to shift your resonance so that there's a balance between head resonance and chest resonance. You should feel the sound coming from behind the bottom part of your nasal cavity, and not from your throat. You are likely trying to force the sound up pulling up chest voice instead. It shouldn't feel like you are getting louder as you go higher.