Okay, the best way that I masturbate every single night is by using a toothbrush holder. Oh my god. It's awesome! If it's the right size. Mine is just long enough and kind of an oval shape. Lube works great with it too because it's plastic and it just washes right off.
I've also used highlighters, [empty] hairspray bottles, etc. Whatever fits. They all work, one way or another.
I use a softball sometimes too. I take a regular sized one, wrap it up in my blankets and put it between my legs. I start humping it and squeezing my leg muscles. Either that, or I'll just use my pillow. As long as there's some type of pressure, it's great. Have fun, and enjoy.