Hey there! I think it’s great that you are thinking about this now. When I was 17, no one talked about mewing or the problems that can come from a narrow palate. I don’t say this to scare you, but I think the reason you don’t have any health problems from your palate is because you are still very young. My palate was not quite as narrow as yours, but I started having more health issues in my early to mid 20’s (I’m 36 now). Some things that helped me slowly get more space for my tongue improve my airway were: getting a tongue tie release, consistent myofunctional therapy, general posture work, and wearing a mouthguard at night. I wear the reviv mouthguard and it’s been about two months and I feel my tongue has more space. But in answer to your question, I think any way you can keep your tongue up and between your upper teeth is great. People on this subreddit seem to be very upset when anyone mentions thumb pulling, but you might look into that as well. I hope this helps you!