Technique accumulation. When choosing a Planche progression for the holds, stay with something that you can hold for approx 5 seconds. Were not looking for each set to be maximal, just to reinforce the position. Tuck, Straddle, Frog, One leg, Parallette, etc are all acceptable. When setting up for the Wall Planche, place your hands hip distance from the wall, and walk up into handstand. Straddling will allow you to decrease the shoulder angle and is recommended for development. Move as slowly as possible sliding down the wall into the planche position. 

A: 10x:03 Planche Hold

B: 10x 3 Wall Planche Negative