Beagle's SCA is intriguing and, to be honest, more difficult to understand (application is relatively easy).
Alternatively, draw a couple of 10 deg fan lines - one from departure point, the other to arrival point. Once you ascertain your position, use the fan lines to figure how many degrees you are off track so far and how many degrees you are off track to go. Add the two numbers and this is the correction you need to apply to reach destination. Simple, expeditious and no need for a further correction (all the other methods require a second correction when you have regained your original planned track).