Thank you all for your suggestions! I am currently practicing the following "rule of 6" i.e always dividing the wind by 6 then multiplying it with the difference in degrees:
e.g 10 degrees difference = 1
20 = 2
30 = 3 (in this case the crosswind will be half)
etc...
Runway in use: 27
Wind: 250 at 12kts
270-250 = 20 degrees difference
I then take wind speed and divide that by 6 so in this case it is 12/6=2
As there is 20 degrees difference, i do 2 * 2 = 4
The crosswind component is 4.
I have been told that this is a more complicated way of doing it, but it seems to suit me well for some reason! :-s
I understand the DI method, and maybe i can try this out next time i am flying.
Thanks all!