I just found this tip on Pinterest and it has already completely changed my life!!!!
Ok, here it is...
Instead of throwing out those last few bits of jam in the bottom of the jar, pour equal parts of vinegar and olive oil into the jar, twist on the lid, and shake. Turn those last few bits into a fruity vinegarette!!! MIND BLOWN! Why did I not think of this? Not only are you not wasting the rest of the jam you already paid for, but you're not going to be paying up to $4 for a bottle of vinegarette salad dressing anymore either!