I finished four bookcase backs (big flat panels of white oak ply)
recently.  I used Behlen's Wool Lube (which appears to be a very
concentrated detergent, not an oil -- the suggestion of Murphy's Oil
Soap might be on target) on 400 grit sandpaper (with a teeny bit of
water now and then) for rubbing out the shellac.

 And then I used Johnson's Paste Wax (the old-fashioned stuff -- I
have a can for my Shopsmith tables) with a pad of the ultra fine
synthetic steel wool.  Works well, in my opinion, and I end up with a
satin finish.

Finish was a light mission oak, slightly yellow/amber to match
existing furniture:

*  Medium or light walnut Watco danish oil

*  1 coat garnet shellac

*  several coats blonde shellac

*  Level with 400 grit (rubber sanding block)

*  Smooth with synthetic steel wool (big wad)

It does have a few shiny spots where the pores are particularly deep,
but the wax evens that up.

Worked pretty well, even though I didn't need a table top quality
finish.  Shellac, as most of us have figured out, is really forgiving.

Ken