Good advice. Usually what I do though, is set the sample to mono and play the pad on the first tick, and go into step edit to make sure it starts where I want it to (some loops you might not want to start at the 1... for some strange reason), and if it finishes early or late in my sequence I adjust the sequence tempo and tuning in the program screen till I get a seamless loop. Also, if you aren't working with a 4/4 loop it will probably never loop properly if you have your sequence set to 4/4... you need to get your timing right. Not every sample is 4/4.
Street tested, Thug approved!