(Wow, I haven't done this in a while)
Okay, so here's a personal tip I have:
Tired of your strings breaking every 5 seconds? Well, I have a couple personal tips that will extend the life of your strings. First off, you know those candles you have in your atic somewhere that you'll probably never use in this day and age? Well, why don't you try taking those suckers and rub them over the strings? The wax somehow coats the strings and thus, gives it a longer life. It's best to do it immediately after getting a string-job.
The next one is one that I use the most. Generally, it's the virtical strings that pop due to friction against the horizontal strings. So, if you look at your racquet strings now--around the sweet-spot area--you can see it cutting through. What you must do is shift all the horizontal strings up (or down) by about 2 millimeters (a little bit) so that it is cutting through a new spot. This technique actually doubled my string life.
Hope that helps.