Wall PPP Questions

How do we properly get into a wall planche for the wall PPPs? I've attempted these only a few times and I believe I always end up arching (legs higher than torso) whenever I get into the wall planche. 

Are the heels supposed to touch the wall or just the forefeet? It's done ideally with socks right?

Are they supposed to be harder than straddle or half lay planche push-ups when done with full lean?

I don't need to do these, but I was going to do some just for the community compilation video. Thanks in advanced!

Cast wall walk down, or up?

They're tough SOB's but i feel that wall maltese pu forces good form more strictly, getting into position makes any arch in my back feel v obvious.

I also generally use a shiny door and walk up and down on it

This is how I do it: start with your feet on the wall and your chest on the ground. Put your hands down by your hips and push up.

Thanks guys! 

Joshua Slocum said:

This is how I do it: start with your feet on the wall and your chest on the ground. Put your hands down by your hips and push up.

I found that to be the easiest way to get into a straight body wall planche too for wall PPPs although it does make the first rep harder by starting with body lying on the ground.