I've seen more rules of thumb on this subject than I have fingers and toes! However, the one suggested to me when training goes like this:
Use 3xWCF on outbound leg unless the wind direction is within 30deg of the hold axis, in which case use 2xWCF.
Add/subtract 1 second per knot of headwind/tailwind to the outbound timing.
From a teaching view point, you can come up with endless extra rules that if applied when planning before flying, and given an accurate wind forecast and if flown accurately will give great results. How relevant this is to the real world when having to take up an unprepared hold whilst hand flying in IMC is a moot point.
After discussing these rules of thumb on holding with my IMC students I try to impress on them that maintaining situational awareness and flying the assigned altitude are the priorities.