what is the proper etiquette on tipping...i imagine tips are expected at an incall establishment, but what about an independent incall provider for example

Some folks distinguish from indy or agency - I'm
not sure why.

Also some confuse the discussion of tipping with
gifts.  Again, not sure why since they're totally
separate issues.

Most provider rates are all inclusive.  Some will charge extra for things like Greek or some fetish play.  In these cases, tips could be given for exceptional service or if you're trying to make a good impression on a lady you want to see again.  Many people never tip.

I'm guessing that when you say "incall establishment", you're talking about AMPs where you pay a massage fee to get in but have to tip the girl for services.  Few providers work this way.  It's called "upselling".  This is generally thought of as almost as bad as being a rip off.

You can find a lot of guys' opinions on tipping if you do a search.

I never saw any evidence that tipping improved future service so I quit tipping a long time ago.  I seem to get good service from my repeats without tipping.

You already gave her the tip in an envelope when you got there.