Hi ntsmith, I think by "crab" (for want of a better term) we mean the plane is not pointing in the direction that it's tracking across the ground, just as a boat crossing a flowing river will be pointing upstream if it wishes to track straight across. In both cases the boat and plane are flying straight through the air (or water) and don't need to be forced to hold that odd angle as they aren't "sideslipping".

Sideslips are good for getting rid of excess altitude without building up too much speed but the later pattern ships knife edge too good, years ago you could really crank in the rudder and get some wild angles happening and you could hear the air buffeting over the fuselage, now you push in rudder and the thing turns around and starts flying away, you practically have to be in a knife edge.

Given you've asked the question in a pattern orientated forum, needing to cross the controls to counter yaw coupling is something that only needs to be done on a badly setup plane (from a pattern perspective), although perfectable acceptable on a non-aerobatic scale plane/trainer/warbird.

Again I wouldn't recommend the one-wing-low method, it may work fine on full scale stuff but it's a really bad habit, plus flying one wing low requires opposite rudder to keep the same heading otherwise you'll fly in an arc on your landing approach. Another negative is that side gusts tend push the plane down and lulls tend to let it float where with the wings level the plane will tend to automatically weathercock into a side gust and maintain it's ground track. Yeah the tail can wag around a bit but it doesn't worry a well set up ship. Honestly, setting your angle on the final turn really helps.