Keys are meant to be pressed with a downward motion, they move up and down. When doing big leaps on the keyboard or playing chords, it helps me to stop thinking of movements in straight lateral lines. Think of arcs, of parabolas. If you make the leap in a straight line, then you actually have to make a sharp corner to play and you have a higher probability to miss or hit the note without any control. By moving in arcs- however shallow or close to the keyboard- you play the keys in the best way possible, you have better control of your weight and over the attack.
The shortest distance between two points is a straight line, except in a piano. The shortest distance for us is usually curved. Avoid sharp turns, stunted movement or sudden stops in your motions; your movement should flow naturally from one position to the next.
[caption id="attachment_295" align="alignnone" width="300" caption="A parabolic curve."][/caption]