well obviously you've already researched the exact weight of item you need to steal @ what skill level... so the best method is to have a guildie leave a packhorse or llama at your house or theirs for you to train on...
1. use any skill with a target or an item that brings up a target and target the item you wanna steal
2. Setup a macro for, Use Skill: Stealing > Wait for target > Last Target
3. Place item inside the packhorse (if you need snooping too this is a great time to also train snooping on guildie's packy)
4. Hit macro and you will fail or succeed.
5 replace item into packy and do it again...
I hope this is what you were looking for sir.
