I just did this for the first time. Had about 1/2 a gram of keif saved up from maybe like a 1/2 of material (i wasn't trying to save it for anything, I just *inherited* one of those screened grinders from an ex girl friend, heh). I just put it all in the corner of a little baggine, wrapped it in plastic using 10% of the baggie at most, then stuck it under the leg of a heavy bed for a night.

I am quite litteraly amazed at the fact that it worked and it's actually really great quality. I didn't use any special material, some good stuff here, some shitty stuff there - whatever was going around - and I ended up with a rock hard block about the size of a dime. it only takes one or two hits to get you right.

One thing i noticed was that what I made was a lot darker in color than what my buddy had going for him (which smells great, but his stuff would turn back to powder a lot easier than mine). i don't know if this is due to difference in starting material or difference in ending material (due to the process of collecting the trichomes)..