Here's my set up for patching:
My little plastic leftover container full of mixed joint compound, an old spatula for mixing, a couple of different taping/putty knives for applying the compound to the wall, and some Elmer's Glue for prepping the wall (you brush this on the area you are patching before the compound -- helps it adhere better).
Another key component of the plaster repair is fiberglass mesh tape. I embedded this in the joint compound covering the larger holes. It gives the compound something to hold onto while it dries and creates a smoother, more permanent patch.
A close-up of the tape outside the wrapper. If you squint, you can make out the tape embedded in the joint compound on the wall behind.
A finished patch waiting to dry!