Something I've learned is that alot of times you want to use opposite forces to drive your punches/kicks. For instance, if you punch, you'll want to use the bottom part of your body to build force. By using the opposite side of your body to drive your attacks, you can often do more damage.When doing kicks it's always nice to move your opponents body into your attack. If you doing a side kick, use grabby hands to pull your opponent into the kick. In judo, if done right, you may find yourself ripping your opponents in half. Here's a kick I developed during my early days in Toribash. Try to perfect it, see what you can make out of it:

Hold all.
Left rotate chest.
Left bend lumbar.
Contract right pecs.
Extend right hip.
Contract left hip.
Extend both glutes.
Grabby right hand.

With kicks like this it's always nice to use abs and ankles to your advantage. Using your chest and lumbar is essential to performing a noteworthy kick. Your lumbar and abs are great for directing your kick. Contract and extending knees are good practices. By extending your knee, you make sure you give all you can to your opponents lumbar. By contracting your knee you can often block your opponents kick. Contracting your knee can also give you a strategic advantage, like being able to launch yourself or have a pending attack ready. Another thing to note about legs is that you can detach limbs from your opponent by closing your knee over that body part. This is risky, however, because if you mess up you will force your own leg off. Contracting your knee is certainly odd business, and I usually don't do it unless I know I should. Maybe this can help you?