How do your clients pay you?

My clients pay me by cash or check in advance

Cash and check

I prefer cash or check, always in advance. I'll use Paypal as long as the payment is not too large (otherwise Paypal takes too much of a cut). I've also heard of an app that let's you accept credit card payments using iPhone, iPad or droid; it's called Square (www.squareup.com) but I've never used it.

Being that i work full time for a gym, my clients pay the gym and the gym pays me. They can use check,cc, or cash, but its not directly to me.

Cash or check.

Cash or check, and in advance for the month.

Preferably check, but also cash or Paypal. All payments in advance.

Cash, Check, credit card. Depending upon the client, I must first perform the work and invoice them.

Check and cash paid upfront ten sessions at a time.

I have come to believe that money is a great motivator. If people pay in advance, they'll show up.