what is a good tip to give a provider who works for an agency ?

I'm not a tipper.  But what I will do, whether she's agency or indy, is not take the discount for booking through P411 or D-C.  I'm sure $25 or $50 means more to her than it does to me.  I will also not pay a grandfathered rate if it's under $100.
But mainly, repeat business is the best reward.

for every lady who provides a good date.

Keep in mind that agency ladies keep only 60% of the actual rate so adding an extra $20 or whichever your generosity calls for, and provided she met or exceeded your expectations will certainly help her, specially if they are touring being that most agencies do not cover travel expenses and the lady has to fork hotel, tickets, meals etc...

-- Modified on 9/28/2013 1:58:53 PM

Don't tip her

Truth, Papasan! The first and foremost of many ways. My other method is to try to tell a joke. They always moan then.

The best tip is a repeat visit!