Nathan Higgins provides the following figures
Normal Ops 10
1-INOP 11
DP 13
YDI 10
TSE 11
LGE 20
However these are conservative, I've been getting much closer with some of the above figures.
I am playing around with track and wind averaging as well
((trk or wnd) x dist) + ((trk or wnd) x dist) + ((trk or wnd) x dist)
Sum of Distances
However I found that with track averaging, sometimes it's easier (and still rather accurate) to get out the protractor and just measure A-B.
Also, be sure to get to know the company policy well... been caught out a few times in the beginning taking 3300kg out for reserves in an inflight question, as opposed to 2250 (company policy stipulates that you only need 30mins fixed reserve when in-flight planning)