I have found the clock-code method to be the best so far, but used with a different method of calculating max drift:
Divide the wind velocity by TAS (in NM per min).
ie: 60 kts = 1 NM per min.
90 kts = 1.5 NM per min.
120 kts = 2 NM per min...... and so on.
So, at a TAS of 120 kts and a wind velocity of 15 kts the calculation looks like this:
Max drift = 15/2 = 7.5 degrees.
Then apply the clock-code method.
As taught by RAF CFS (Central Flying School).