There's no real trick to them. I would pick a set that has a lot of ones you like so you increase your odds of getting one you'll keep. Most stores will have a station where you can trade them- they'll either have three visible ones or you can try your luck with the mystery box and pick a random number. In every set they usually have 12 different kinds. One of those will be a chaser. In every case there is only one chaser but there are two of every other one. Hope this helps :D - MayBie  1864.2 #40 11:54AM

My girls have some sort if a system! They weigh in there hands, shake it and wah la they always get the ones they want! - WickedWench  576.2 #190 12:03PM