In the surf the wave usually takes the board with it & I sort of "body surf" after it on the next wave's white water. Seems a bit quicker than immediately dragging & your boardies don't end up round your ankles.
Losing it behind the waves the board's almost always upwind of me so if I can't see it over my shoulder I'll just focus on 3 or 4 really strong body drag tacks (pretend you're a rudder

) then as nikmcc said boost yourself & look around.
That's just my way though, might be location specific with different currents & whatnot.