Crosswind
Even simpler, and more accurate, than the previous reply, take the number of degrees the wind is off the runway heading, divide by 10, then divide by 6. The crosswind is that fraction of the wind strength.
So if Rwy is 020 and wind is 040/12k, then wind is 20 degrees right of rwy heading. So 2/6 of 12k = 4kts xwind from the right
Example: Same rwy and wind stength but the wind direction changes
Wind 020 -diff = 0, so 0/6 = no crosswind
Wind 030 - diff = 10, so 1/6 = 2kts
Wind 040 - diff = 20, so 2/6 = 1/3 = 4kts
Wind 050 - diff = 30, so 3/6 = 1/2 = 6kts
Wind 060 - diff = 40, so 4/6 = 2/3 = 8kts
Wind 070 - diff = 50, so 5/6 = 10kts
Wind 080 - diff = 60, 6/6 = 12kts Full crosswind component.