The wind is 100% efficient. if you have a 10 kt crosswind, and you hold a fixed heading for an hour, it will blow you 10nm in its direction. The most simple method is: hold a fixed heading, and every 30 mins or less get a fix. You will be half the wind speed off track, or if it is a headwind, you will be on track but half the windspeed short of where you should be. Make a sensible correction, and keep going. It is rare to go more than an hour in one direction anyway, especially in a helicopter or in the training environment.
If your map reading is so poor that you haven't had a fix in the last hour and found yourself less than 10nm off track, you shouldn't bother getting off the ground.