Are you opening Unpaid Item Disputes against those deadbeats?
When you win a UID, you get your FVF back and he gets a Strike.
And you are helping your fellow sellers who Block deadbeats.
Are you Blocking bidders who have UID Strikes?
If you do, the deadbeats can't even bid, nevermind blowing off payment.
Are your items really suitable for auction?
Would you do as well, or better, by listing at the Fixed Price you really want and adding Immediate Payment Required.
IPR means that the listing remains active until someone actually pays for it.
Are your items mobile-friendly?
Partly related to the auction/fixed price question.
Phone bidders may have forgotten they bid by the time your auction closes.