Lots of good advice here, none of which I have any issue with. After mastering the basic techniques people have mentioned, you can allow yourself the luxury of tweaking a bit for your own aircraft and conditions. The main thing is not to develop unsafe habits based on folklore. For example, you might find you're comfortable using 20 deg instead of 30 (or 40) deg flap in your C172, and adding a very few knots, in a very gusty crosswind situation. Just make sure this doesn't become an excuse for far too much approach speed, or touchdown without a proper flare.
While I prefer to land with as much flap as possible, and as slow as possible, I have slightly revised my view since starting to fly very light aircraft. Even in a C150 you can do very well with conventional techniques up to quite high cross-wind limits, as Pilot_DAR notes. However, if you are flying an aircraft of (say) <2/3 the weight of the C150 and commensurately lower book speeds, you do start to become a bit more legitimately concerned with gust variations. In effect, the gust values can start to become a big fraction of your flying speed. By using a bit less flap and some slightly faster speeds you push yourself out of the ridiculously low speed regimes these little puddle-jumpers can operate in.