I check mine everytime I restring them. I am lucky though and don't have sweaty hands and I am not gigging regularly, so I only need to restring once every 6 months or so (even longer with the SOB strings). I am lucky in now having inherited just about every tool that Stewart MacDonald sells! Having the right tools does make life uch easier (especially in fitting new nuts and dressing frets). But even before I had this I would do my own setups. I did a one week course with Stephen Delft in the 70's on guitar repairs and setups which was great. If you are going to do it and want some books, check out Electric Guitar Setups by Hideo Kamimoto (he also wrote another good book called Complete Guitar Repair).