I always go in increments of 5, but it depends on how well you know the solo. If your fingers seem to play themselves at 108. After a few practices, you may be able to boost up to 120 for alittle bit of a challenge. But I would suggest boosting to the point, where you still have control of what your playing. What I mean is your not pushing yourself to reach the speed, you know exactly what your playing. You should be comfortable, you'll learn faster if you are. Plus you won't get sloppy, and your connection with the guitar will be alot better when you go on to attempt difficult stuff. Be patient brah.
BTW congrats on getting Host.
"My whole life is a dark room...ONE BIG DARK ROOM" - a.f.i.