I have started to use Stirling's mentholated pre-shave soap while preparing my normal shave soap. It is very slick and lubricates while giving some coolness to the shave.
I am a big fan of PAA’S cube Preshave Soaps and believe it has had a positive effect on the closeness of my shaves. It adds to the slickness of the soap I use and seems to lessen the number of passes needed for a BBS.
My "pre-shave" item is always done in the shower...any of a select group of Men's Body-washes. Some are in gel form, others look like leaking chalk. But they all provide great comfort to set things up for the shave.
It's been my experience that just a washcloth beard soak with hot tap water to hydrate beard works best for me. For many pre-shaves may work but I've tried pre-shaves and for me are no better than water. A good lubricating soap like Cella or Arko (bowl pressed) is a great cushion between blade and skin, the hot tap water softens and hydrates the beard, a good soap cushions, keeps beard hydrated and slickens the shave. On a side note, I've noticed that with some soaps, if not rinsed off thoroughly will cause me some irritation.