flight sim practice
I like the alternate instructor idea.
Here is a cheaper idea that worked for me and is, in my opinion just as good. I run X-Plane 8.32, but it should work on other flight sims. Crank in some heavy winds, say 15-25 kts. at about a 60 degree angle to the runway, and practice on the sim until you can really control the flight path and stability of the aircraft on roundout. I hasten to add, this is a practice thing and if you have not already learned the basics of crosswind techniques you will have to learn them first at least theoretically. Flight sim practice solidifies flight skills, but does not teach the basics.
As for the basics of crosswind approaches: crab to maintain centerline of runway while away from the airport. When getting close to the touch down zone, transfer your flight configuration over to a sideslip. Your upwind wing will be low compared to the downwind wing. Your rudder will be cross-controlled in order to maintain alignment with the runway.
Don't use flaps at any time during crosswind approaches if the winds are strong. Keeping flaps up to minimizes the tendency to buff up and down and keeps wingloading high. A C172 can be landed with no flaps.
Touch the upwind wheel first, followed by the downwind wheel, followed by the nosewheel as usual. Raise the upwind aileron gradually as you roundout, and the air loads decrease. This will protect against gusts.
Speedwise, use slightly faster speeds than in non-crosswind approaches. This for a 172 might be 60 kts. toward the time of touchdown. This gives the airplane more momentum to deal with gusts and enables not using flaps.
One more point that seems relevant- crosswinds are best studied in taildraggers. I did not know how to use the rudder until I got a tailwheel endorsement. Tricycles are so forgiving of poor technique in landings, most new pilots have no idea what the rudder can do for directional control.