I fully agree with adlerdriver, this is how it's taught in JAA country(at least in mine).
To refine it further, if you have the winds aloft, you can calculate the drift angle very easily.
For a crosswind, you can calculate the crosswind component as follows:
For a wind from straight ahead, there is no crosswind component , crosswind from 30 degrees, multiply by .5, for a crosswind from 45 degrees multiply by .7, for a crosswind from 60 degrees multiply by .9 and for a crosswind from 90 multiply by 1.0.
To translate the crosswind component to a drift angle divide the TAS by 60! You then divide the crosswind component by this factor to give you a drift angle. For simplification purposes just divide the crosswind component by to for approaches(done around 120), by three for holdings( for speeds around 180) or by 4 for higher holdings, or enroute below 10.000.
For example, you have figured out that the track you have to fly is 180. The wind is from 210/30 and your TAS is 180. The crosswind component is .5 times 30=15, 180(TAS)/60=3. 15 divided by 3 is 5 so you have to steer 185.
Method is great to make sure you don't exceed crosswind limitations on landing for example too.
Just remember 0, .5, .7, .9 and 1.0 for crosswinds from 0, 30, 45, 60 and 90 degrees!
The same works for headwinds, just turn it around 1.0, .9, .7, .5 and 0! In the above mentioned example multiply 30 by .9 and you get a headwind component of 27. Try it on an e6B!!
The former is simple cosines calculus, the later sinus calculus.
If done correctly, you can nail a holding pattern on your first lap!!