There are completely different tipping structures, depending on where you go.
If you go to a holistic spa, you're going to pay $40 for a 30-minute room, and then you'll negotiate with the girl for the rest. Maybe $80 for body slide, or $120 for FS, but it depends on the place, the girl, and you.
If you go to a massage parlour, like Premier, you're going to pay reception for the room and the girl's fee, which includes the VIP massage (naked people, touching, happy ending). If that satisfies you, no special tip is required. She's made her $100 already. If she's amazing you can give her $20 or $40. (I gave Sarah $50 when I saw her.) If you want extras, then that's going to be extra. At Premier, standard is $50 for her mouth and $100 for full service. That's if she'll do it at all, because many of them don't. Some are known for charging more. Other places might have different price points. I think it costs a lot more in Brampton, and fewer provide.
If you go to an escort with an agency, your extras are included in the fee. You get FS covered by your fee. You're free to tip on top if you want, but it's up to you. I gave Arya $50 once. (She's my avatar.)
If you go to an independent escort, or SP, her fee suffices, and she isn't expecting a tip on top, but again, if you have a really good time, you can tip.
I don't follow the semi-legit places well enough and Krayjee's threads are too long. I think you tip $40 for a happy ending unless you want to touch her a lot, in which case it'll be $50 or $60.