I think the best projection technique is the High Level projection technique listed in Astral Dynamics. I use it for all projections, not just high level. The extra energy justs helps for anything metaphysical.

I also use the high level technique as my primary personal development tool. Two birds with one stone. I get awesome primary center development, and then I can project and have fun. Win win

Warning: Dont do this technique unless you developed tertiary energy body, secondary energy body, and lower chakras.