Make it Easy to Get the Tires On/Off
Two secrets that can make it much easier to get a tire on and off the rim are to use a thin rim strip inside the rim (I’m not talking about its width but about its thickness: a good one is the ROX rim strip), and to use a tube that’s one size smaller in width than the tire you’re using. For example, if you use a 700 x 25C tire, use a 700 x 20C tube.  
 

Stand Up Your Road Rig
When you get a rear flat on your pavement pounder, instead of laying the bike on the ground after you’ve removed the wheel, try standing it on its front wheel. Just set the bike so the front wheel is on the ground and rotate the rest of the bike upward. When it’s almost vertical, the frame will touch the brake supporting the bike. This won’t work on all bikes and you may have to move the bike a bit to find the balance point. But it looks cool when it works and it keeps the bike nice and tidy. 
 
Always Carry Boots
Boots are tire patches (not to be confused with tube patches). Boots are used when you ride over some glass or swipe a sharp rock and put a gash in your tire. If you just put in a new tube, when you pump it up, it’ll expand through the hole and KERPLOW! explode. Bummer. But, if you’re packing a few 1- x 2-inch boots (made of any tough material such as denim or nylon or sail cloth), during tire installation you can slip one between the tube and tire and you’ll be rolling again (though the tire will have a bulge, the tube should stay inside long enough to get you home).  
 
Pump Right and Save the Valve
Presta valves are relatively delicate and they can break right off if you’re not careful when pumping up a tire with a frame-mount pump. To prevent this, reinforce the valve while pumping by holding the end of the pump with part of your hand and at the same time wrapping a finger around a spoke and resting your thumb on top of the tire. (If your hands are small, you may have to do one or the other.) Just do your best to support the valve so that when you’re inflating the tire, the valve is not taking the brunt of your pumping force.