How to train myself to be more Grounded

Hey all, Lucario main here (I know, we exist), and I have a really big issue of jumping too much and I wanna know how I can better practice being more Grounded, doing more short hops consistently and just not getting beaten in the air, I got waxed by a mewtwo last night and I feel like that was what happened to me a Lot, ty for any advice!