It completely depends on the client. Those who 'listen carefully to your advice so they can totally ignore it' are no fun to be with. They have the habit of doing the opposite and then blaming you for their mess ups. The diplomacy is sometimes the hardest part of the work and can drain you in no time.
"There is a fish rising nicely. Try to land the fly about 2 yards upstream while keeping low so the fish doesn't see you"
The angler walks straight up to the fish, spooks it and spends the next five minutes casting at the boil it made on the surface when it shot off. What do you do?
There are people I really enjoy looking after. Some of the old Gents and Lords are wonderful company and although they usually aren't great Fishermen, they often once were. Out one afternoon though, after Mayfly trout, one such angler had a large amount of line in the air preparing for a far bank fish, when a big fish engulfed a dun under our feet. He stopped the line in mid air and landed his fly on the fishes nose with a breathtaking display of skill.
I am not a professional Guide, only doing about a dozen days every season, so the tip is not important at all to me. Tipping can be such a messy business, a 'Thank You' means much more.
River Keeping and Guiding are two entirely separate jobs. Good Keepers make **** Guides and a Guide will
never make a good Keeper.