Like everyone has said, slow down in gear and the engine won't use any fuel. Thats why the Inst. Compsump. figure on the trip computer goes to 99.9MPG.
I now have stopped changing down gears and stay in the gear I am in untill the revs get to 1000 then dip the clutch. If turning, I change from what ever gear I am in to the one appropriate for the corner (5th to 2nd, 3rd).
In my last car I would have gone 5th,4th,3rd and 2nd then pressed clutch to stop but I don't think all the extra clutch presses and the engine RPM going up/down do anything any good.
I'd rather use the front brakes a bit more and replace them than replace a clutch.
To get back to the question, I would only use 1st from a complete stand still. Anything more than a couple miles an hour and second is fine.