First of all why should you tip some one for doing his/her work?
Their employer should pay a normal salary
You are paying the required price for the accommodation, come in stay one night, clean up, do dishes etc etc
I was was brought up, clean your own mess

and leave it as you found it.
Though knowing an extra is a welcome I always leave something (goods or money)
Bringing toilet paper because there was not any is not going the extra mile but it's basic.
But if you are messy and you know that it will take extra time to clean it up then you DO leave something.
We know the life of a camp attendant at a wilderness camp is a lonely one, without family, TV, comfort of home, but that doesn't mean he should come by around dinner time with an empty plate asking for some 'leftovers' We hadn't eaten yet ! or anything else was good too when he noticed food was not ready for consumption yet. On the other hand everytime there was a sighting nearby he came and told us about it encouraging us to leave and see for ourselves. Every morning we gave him our 'leftovers' with a cooldrink for lunch which he gratefully accepted. And yes when we left we gave him some extra, because we found him inventive in his own way.
Do you tip a guide? I think that is really difficult
Once I had a guide in Karoo doing Pienaarsepas early morning, bitter cold chatting away for hours. Giving us so much information about the area, animals, people, his thoughts and believes ! it was a amazing and yes we did give him extra for which he was very grateful. A year later when we met him again telling us he was going to do that days sunset drive we signed up for it and again we had a most informative drive and awesome sightings.
And I saw everyone giving him something, because he and his spotter earned it going the extra mile.
It's already normal to pay the extra 10% on the bill and some rands for cleaning car windows at a petrol station. But why should I pay a car attendant when I'm parked at a mall where parking is free (part of the service) and all he does is whistle when I get out of my car expecting me to hand over money at return for what?
Bottem-line for me is when some one does do something extra I'll thank them for that, words, goods or money, but it's not naturally.