For aikido, you want to always keep your feet on the ground. Occasionally go aerial to tip them off, but only when you're sure of it. Another nifty thing you can do that actually works is moving around a lot while still holding onto your opponent. Don't focus on just trying to take them down that one moment. Move near the edges of the dojo and then decide to pin, throw, or turnover.
As for judo... eh, not sure how I can help you there. Kick 'em in the sack, I guess.