Advice needed for keeping goggles in place during race start

How do I keep my otherwise well-fitted goggles in place when I hit the water off the starting block, BESIDES making them tighter? I never used them in high school meets, because of the same problem. But, I really DO want to use them now in my first Masters swim meet... Problem: I have a narrow face and bone structure that makes goggles very difficult to fit. Trying them on the same way I do a mask (making sure there is good suction w/o the strap on), I finally found the last pair to fit, after trying every single model on at ***'s Sporting Goods. I ended up with an Aqua Sphere that I like that doesn't leak water and stays in place comfortably when I swim. BUT, even when I tighten up the strap, it still slips when I hit the water off the blocks, even while wearing a cap. I am trying to get my arms and head in the correct position, but I am still not sure what I am doing wrong. (I've been watching You Tube videos, since I am swimming most of the time on my own, because I am located too far from the closest Masters team.) Any advice would be most appreciated! Thanks! Elaine