Vaseline can be used as masturbation lube.
I use Vaseline a lot to masturbate with.
It's not the best masturbation lube but the Vaseline or other petroleum jelly does work good for masturbating and it gets pretty slippery.
The Vaseline or petroleum jelly also protects your penis from drying out as well.
Lotions such as hand lotions or even your own spit can be used for masturbation lube.