I love kitchen tricks. Did a cursory search of the board and didn't find a thread, though there may be one. Love to hear everyone's innovative improvements to kitchen life.
A few, perhaps common:
Stock and demiglace frozen in ice-cube trays, then downloaded into big ziplocs, easier for sauces.
Rolling pie crust between pieces of Saran, which keeps it from getting warm, overworked, and sticking to things. Peel off one side, lay in place, peel off other side.
Ice cubes on floor of oven for some bread baking, to simulate steam convection (Pierre Franey)