[Yodaman]

Forget painting shims, put a bead of caulk around the base of the cabinet. If the gap is too big maybe molding is in order, then caulk around that.

 

[Yodaman]

If the vanity is going on top of a finished floor where you would otherwise see the shims, you can also scribe (cut) the bottom of the vanity to match the floor, rather than using shims.

Yea, I have watched Norm on TOH trim cabinet bases, but does anyone really do that? Very few I would guess, but it is a option.