Shortcuts and Substitutions

[whyintellectual]

Today I was making spaghetti and meatballs and realized I only had 1/3 of a jar of sauce left.This was problematic because I brown my meatballs on two sides and then let them simmer in the sauce to finish. In a flash of brilliance, I decided to drain a can of diced tomatoes and added my leftover sauce and managed to make a pretty tasty concoction for my meatballs to complete cooking in. No complaints from the boyfriend. He loved it.

So now I am wondering...

What are your favorite shortcuts and substitutions in the kitchen?