There are a lot of free guides on this here i'll link you to some of them,
Please do not sell guides that are either
free or patched in this section,
Proof :
http://www.youtube.com/watch?v=0BPwYuFRNSg
Also it could be found all over youtube,
Even if you type in fastest thieving xp on google this is what you'll find,
Also if your method consist of Pyramid plunder that method is also all over the internet,
Wouldn't wan't anybody to buy a guide that they will find everywere on the internet 5 minutes after purchasing,
If neither of those are your methods i'm sorry for this post and please consider this as a free bump.