Once I make sure every new bow I get is properly tuned, I do one simple thing to help me keep track of it's current tune. Use a fine point paint marker and make a mark on each cam right beside the limb. Every once in awhile check the marks. If they have moved, something has happened, stretched or something. Sometimes it is as simple as putting the bow on a press and putting one or two twists in the string or cable to get it back where it ought to be. If it has moved a lot, I take it to the Pro Shop. Hope this helps.