I've got a few...(all third and fourth years/residents, please see my note at the bottom)
Find somebody that seems slightly smarter than you to study with, who has the same study schedule as you. I studied with another night owl, usually until four or five in the morning each night the weekend before the test, slept until about 12 the next day, then did it all over again...excellent cramming was accomplished, and both of our grades started shooting through the roof.
Don't get a palm pilot, don't get a steth or an opthalmoscope. Definitely don't get a panoptic (500 dollar gunner opthal. that looks like a radar gun), all of these things can wait until second year. That is, unless you have some sort of clinical medicine class your first year where you actually see patients. I got my nicer stuff my second year, after i had had a chance to see what everybody else liked/disliked, and got by fine with a cheapo steth from a drugstore until then. All you will do with a palm pilot is play with it during lecture, then end up having to buy a new one two years from now when yours is hilariously outdated.
Don't study near a computer, like somebody else said. It calls your name, and you will give in. Every ten minutes.
Don't assume that the library is the best place to study. Other people will see you and drop by your study room assuming that they are your sole source of comfort for the upcoming test. What they really want is to see if you are studying more or less than they are. They will say that they have already read everything twice or three times, and are just reviewing everything now. This is a lie. They are probably more behind than you are. I suggest studying at home, in your closet if you have to, but nowhere near a remote, computer, bed, or stereo. Just my humble opinion.
BRS...don't know if this will really help you study for most classes. I find them to be scant in the information that you will be tested on (even if they are high in relevancy...the prof's don't care about that). You want a great way to learn? Find somebody with last year's transcripts/scribes/whatever you call them, and print them off the morning of class. This helped me way more than trying to scribble things down in the margins of the handouts, plus I looked pretty damn smart sometimes.
Skip class if you want to. It's not really going to make that much of a difference. Some people will tell you that you can't learn if you don't hear it first-hand or whatever, but that's just what works for them. If you need to hear it, go. But most people can get by just fine by reading the transcripts. Just get a buddy to pick up the handouts for you when you skip. You will need them for the pictures if slides are to be shown on the test.
That's all I can think of for now. Anybody who is past the basic science years, please post more of your advice for the clinical years. I find this stuff incredibly helpful and insightful. Thanks guys.
-KE