But don't expect it to really skip all the machines, particularly if you just drop it in a collection box. Very little mail is processed by hand.

In addition, loose items are against postal regulations. Make sure it is adhered to a piece of paper or something so it doesn't slide around.

Personally, I never do this (I always use bubble envelopes and pay for package shipping). But if you want to take the cheap route and risk loss or damage, those are the steps.