Massage Therapist

Average Tip: 10 to 20 percent of total cost.
Exceptional Circumstances: Tip 20 percent if a therapist clears her table for you on a busy day or puts in extra time on your knotted shoulders.
Things to Consider: If a therapist comes to your home or hotel room, ask ahead of time if the tip is included in the fee.

Cosmetologist at a Department-Store Makeup Counter

Average Tip: Not required.
Exceptional Circumstances: Many work on commission. If the person has done your makeup, buy something.
Things to Consider: Loyalty is more valuable than tips. Note her name, and return to her counter when you need more products.

Helpful Nurse

Average Tip: Usually not permitted.
Exceptional Circumstances: Small tokens of appreciation, such as candy or flowers, are acceptable. Thank-you notes are also appreciated.
Things to Consider: Since nurses work in teams, direct your gift to the “floor” of the hospital, rather than to individuals.

Car-Wash Attendant

Average Tip: $2 per car for a standard wash.
Exceptional Circumstances: Tip $3 to $5 for an SUV or any other large vehicle. Tip 15 percent for a detailing.
Things to Consider: Many car washes pool employee tips. If you want to reward an individual, tip him personally.

Valet-Parking or Garage Attendant

Average Tip: One-time parking, $2 to $5.
Exceptional Circumstances: If you pay for monthly parking, tip only at the holidays — $25 and up, given to the garage manager.
Things to Consider: For valet parking, tip the guy who brings you your car, not the one who takes it away.