(1) Patching tubes on the road sucks. So I carry two tubes, in addition to the patch kit, tire irons and pump. I patch my punctured tubes at home, bu I haven't had to patch a tube on the road in a long time.

(2) On longish climbs, slide your butt back on the saddle for some extra power. Also, every so often, shift up a gear and stand for few pedal strokes. This is not for the power, although you will generate some additional power at the cost, but just to change the muscles you are using for a little bit. Don't stand for too long (unless you are racing or training to race) because it takes more energy to stand and pedal than it does to sit and pedal. But standing for a short while every so often is like a mini-break for the leg muscles that are going to do the bulk of the work getting you up the climb.

(3) Never, never, never try out a new part, new clothes, new anything in a major event ride. The day you are going for your first century ride or that race you've been targeting all season is not the time to wear a new pair of shorts or break in a new set of brakes. It is a recipe for unpleasant surprises. The same appies to races, tours, etc. Try out the new stuff on a routine ride where it will not be the end of the world if a problem comes up.