or using the figures from the last post and imagine the old analogue type wrist watch .
so if its 15' off runway use the 1/4 past position (15mins) so its a quarter of the dial/hour so quarter of the strength. 20' off use 20mins which is one third of the face/hour so a third of the strength. if its 45' off use the 45min position so thats 3/4 etc etc. anything over 60' just use full strength. much easier than having to use your brain to work it out !
so in summary - whatever the wind angle - use the same figure in minutes on the face of your watch and then its just the proportion of the minutes to the full hour ! even i can use this technique.
failing that ignore the wind shut your eyes and hope for the best !