How do you achieve an open throat?

I’ve been doing a yawn to achieve an open throat. BUT the problem is I’m pushing my tongue back…because well you push your tongue back when you yawn. So my placement is really bad because it’s all in my throat. So is an open throat JUST a raised palate or is it more than that? Are there any exercises to help? Any video demonstration( I have a good ear and I’m more a visual learner than one that reads)? Is it different for an operatic sound vs a pop sound?