easy, step-
1) Find a Middle..the trade forum will have a posting titled"Middles and scammers list"
2)Ask said trader to use one of the middles listed. After agreeing on one.. move to step 3
3)Ask said Middle if they would be willing to middle between you and other player. If yes..move to step 4!
4)Send everything your trading to said Middle, remember to add a note with what is being traded and with whom(a middle could be dealing with multi transations at once, this helps the middle termendesly).
5)If said trader is active, items will be in your inventory in a short time..remember a Middle is a respected player of SWC, so it might take some time for them to transfer back and forth. 7 days is the most you should ever wait to get something.