I sometimes like to tell Amazon that I didn't receive my parcel if they leave it wherever without my permission.
I take the parcel and the refund. 

Note:
Only doing this to Amazon. I know it might hurt the drivers, but they actually are not allowed to do that and are reminded of it often (I worked at amzn). Also had a few expensive parcels stolen because of that.

What kind-of-stain-free scams/hacks do you know and use?