Off the top, Its a rather vial substance to chop & sniff-it burns hella & it imparts an overpowering noxious chemical odor in your sinuses. The back drip is especially unpleasant if you've never indulged in this before. If you're the sort of person that has a sub-addiction to insufflating as their ROA, you may just prefer ingesting it this way & shouldnt have a problem doing a .1 line, which would be described in the community as a rail. It would take an experienced user to sniff up a .2 sized line in one pass of the straw I would think. Also, this drug is notoriously fiendish, & its very hard to resist the compulsion to redose. Of course, the quality of said product is a factor, but from what I can tell these days, high quality "ice" is consistently available if you have access to good shit. I almost forgot to mention that a little goes a long way when you smash a shard, it seems to expand in volume. All that being said, I'd advise starting with a .05 line, which will be fat. You should be instantly twacked if you got some high grade material. Maybe redose every 90 minutes after that with .02 or so for an extra jolt. Be prepared to stay up well past 24 hours from the time of your last line, if not 48. Dont worry about eating either, food will be the farthest thing fom your mind & almost physically impossible to consume. Make sure you drink alot of water, though-this shit can make you sweat from every pore, from the palms of your hands to the soles of your feet. I believe in personal responsibility as far as drug use is concerned, so I would never tell anybody not to do any particular drug, but take extreme caution when dealing with this one, the scene that's involved with it is rather unsavory the deeper into it you get. It also has the tendency to rewire your thinking process & can lead to very poor choices. If you do happen to be the sort of person that can realistically be responsible when it comes to personal entertainment, meth can be really fun to party with & can even be an enhancement device for social interaction.