I know tipping is not expected but always appreciated. My question is, assuming I would tip the lady I've seen, how should I handle it?
Just pick a bill and give it to her saying "thank you for the wonderful evening"?
It seems a little bit rude to me.
But maybe it's because in my country tipping is not used...

Leave it on the dresser or next to the envelope if it is still out.

I do it exactly like that. Doesn't seem at all rude to me.

When I meet someone for the first time I bring a second envelope with a Thank You card in it, along with what I might tip.  If at the end of the session I want to give her the tip I hand her the second envelope; if not I keep it in my jacket pocket.

I was thinking about having a thank you card or gift card handy in a 2nd envelope for afterwards for when I see my first provider next month.

Sometimes I might tip with cash and have never had a lady think its rude but most of the time, especially with someone I've seen before, I have a gift card in a little thank you envelope ready as a tip. More often than not the lady has responded that it was a sweet and classy thing to do.

I hand the lady the money. Never got a complaint or saw sign that she was disappointed in how I delivered the tip.

I usually just leave it on the dresser while we getting dressed and say nothing.  However last week I was doing a role play scenario of a boss interviewing a job applicant.  At the end of the session I said this is your first bonus.

Because, you don't know how the service is going to be. Mine also!

I've never had a problem handing the money directly to the lady during our goodbye kiss and thanking her for a wonderful time.

To maintain plausible denial for both parties IMO money (including tips) should never be directly handed to the Provider.

At the end of the session, what is left to plausibly deny?

But I do agree with you which is why with regular ladies I often get the finances out of the way days in advance with no connection to the date.  She and I know the books between us and that's all that matters.

and I have done my research and know I am gonna have a good time, I bring gifts, which if you have read my reviews or posts, you already know about.

By doing research, you should know if you are going to have a great time or not.  IMHO, this is a must.  

So, I can't help you on tipping.  But do your research for all your dates.

Swim

money that is left on the table can be interpret as accident whereas money that goes from hand to hand can not.

A lot of interesting hint.
Thank you everyone!

I've only seen two providers in my life,(although the same one many times!)and the first time I handed her another envelope with the tip in it.A few times I just gave it to her sans envelope.Once or twice I gave it to her in a card.The inside was blank but I wrote a sentence or two telling her how much I appreciated her and our time together.
AB