I am going to admit to one in the hope that it will encourage others to come out of the closet.
I have been known to grab a tin of Campbell's cream of mushroom soup to make a fast sauce rather than work from scratch after a hard day at the office (I know some of you indolent types may have to imagine any sort of day at the office, but bear with me).

What shortcuts have you taken that actually work out pretty well even if you wouldn't normally advertise your secrets? A sneak addition of some Lipton dried onion soup mix to some sour cream? Or.....?