They aren't going to suggest a tip--no one who works for tips should suggest it. These are the folks in service fields who contract for their equipment or space or who work for lower wages because tips are assumed.

There is also the seasonal versus per incident tipping to consider. I think this kind of service needs a tip at each occurance:

Hair stylist/ cutter
Cabbie
Tour guides
AAA drivers
Drivers at the airport used car lot
Sky caps
People who work in salons (day spas, etc.)
Hotel maids, bellman
Waiters/waitresses
bartender
Caddies
etc.

Plus, if you go to the same hair stylist every month, then a holiday tip equivalent to the amount of a regular visit is appropriate. I have my hair highlighted every other month, so I average the difference between the cost of just the haircut vs the highlights and the cut. The newspaper carrier should get a holiday tip--in the old days when kids delivered the paper and collected every month a tip at that time would have been appropriate. Apartment doorman, maintenance workers, etc, should get a holiday tip.

Tips about tipping.

SRS