Balancing front and rear wheels makes a HUGE difference on the highway!
Pick-up a pack of stick-on-weights from Harbor Freight or your favorite moto shop. I stick 'em inside the rim (in the dish), tape them down, and put the rim strip over them. And, it doesn't seem to make tire changes any more difficult.
Balance it on the axle by spinning the wheel (vertically) until it stops. Add weight on the top side (typically opposite the rim lock) and repeat until the wheel stops in the same place.
Gravity pulls the heaviest part of the wheel to the bottom. If it's way out of balance, you can feel it on the stand/bike as you spin the wheel. The wheel will visibly speed up and slow down as that heavy spot "goes up" and "goes down".
A perfectly balanced wheel will have no heavy spot - Gravity pulls on all the "pieces of the pie" of the wheel equally.
When you spin it, friction will stop the wheel at a different spot every time. This is your goal.
Spin the wheel, let it stop. Spin the wheel and let it stop again. If it stops in the same place, that's the heavy part of the wheel. Add a weight to the top.
Spin the wheel, let it stop. Spin the wheel and let it stop again. Did it stop at the same place again, or a different spot? If you spin it and let it stop again, does it stop at a different spot, or same spot as before?