There are some really great posts about this on two different threads here on the Nexus. You aren't going to get breakthrough effects with the ecig approach, but people are having some very interesting results from a 1/1 ratio, no nicotine, 50/50 blend of VG/PG. You can do it with the stuff you buy over the counter at a smoke shop, but it's better to order pure PG and pure VG online and mix it yourself.
Good luck, young skywalker!
All of my posts are entirely fictional. I am a writer, and as a means to research the life of a fictional character that I'm writing about, I post on the Nexus to get into character. In real life I have no interest or interaction with mind-altering substances.