I have made it a couple times from the spent leaf hops in my strainer while my wort is cooling.
I use a citrus juicer that looks like a pair of pliers:
I have the yellow one of these around anyway:
Leaf hops are very compressable, just load it up, squeeze. leave those hops in fill it again, squeeze, I can get probably what was half an ounce of hops in the lemon sized squeezer.
I squeeze into a coffee cup. Rememebr there is some pretty sweet wort in this too.
I ususally get most of a coffee cup of hop tea from a typical APA. One squirt of honey for me, that green stuff is pretty darn bitter.
I sleep like a lamb after that. I have never tried making it from scratch, I think the sweet hot wort in with the squeezins helps make it palatable. Heck, throw some DME in some boiling water and go man.