Tips for flying on a plane (ear pressure)?

Hi! I'm going on the longest plane flight I've been on in a while soon. I tend to have a lot of issues with ear pressure/fullness, ESPECIALLY with pressure change (on planes and even in cars), and usually yawn to combat them, but recently learned my problems may be due to TMJ, so yawning for 6 hours straight doesn't sound like the best option.

Does anyone have any tricks to relieve ETD in a safe way while on a flight? Thank you!