To stay fluidity, don't lock your whole body, and stay relaxed. To jump better, you'll need to use your ankle joins more and extend them to give you more air. To stay balanced, don't let one joint (say the arm) over power the other, like, don't let one limb be higher than the other. I don't parkour or spars much. So I do mainly combat mainly to win. But it's always fun to look all smoothly when breaking your opponents throat open.

Hope this helped. ~Neighborhood Siren