Dont do it! Money orders are almost always scams
With Craigslist, deal locally and only in cash. I found a concert ticket on CL today. I am meeting the seller at a gas station with cash.
Offers to mail a check or money order are almost always scams. The money order/check is normally fake.
If you mean he wants to send you a money order, have him do so by regular mail. In my experience, money orders are cheaper at the Post Office than most anywhere else but grocery stores also sell them. I think Western Union is wiring money, not a money order, but I could be wrong.
So...have him get a money order, make sure he writes it payable to you and signs it, and then when you receive it, you can either deposit it in your bank account or cash it. I would ship the shoes AFTER I receive the money order.
The money order can be deposited into your bank account, or you can cash it at your bank or a post office.
Don't ship until you get paid and actually cash the money order.
Never ever send extra money back. That's a sure sign of a scam.
You're going to get scammed! You need to meet the buyer face to face and accept cash only, otherwise you should call the deal off!
For CL, NOTHING but sale to a local for cash in hand works. Would YOU buy shoes this way? F*** no. it's a scam.