Dog Groomer

Average Tip: $5 to $15.
Exceptional Circumstances: For a dog that’s large, shaggy, or snappy, tip at the high end. Add a few dollars more for free extra service.
Things to Consider: In Los Angeles and New York City, dogs often get more pampering, and dog groomers may get tips of $50 and up.

Clothing Salesperson

Average Tip: None.
Exceptional Circumstances: If a salesperson went all out to find the perfect outfit for your sister’s wedding, send a thank-you note or a small gift.
Things to Consider: Cash tips or costly gifts are discouraged or prohibited in many large chain stores.

Barista

Average Tip: Spare change.
Exceptional Circumstances: If your regular server places your order the second you walk in, thereby saving you wait time, tip $1.
Things to Consider: If you use a prepaid card, tip a few dollars at the time of your purchase, rather than on a per-drink basis.

Takeout Cashier

Average Tip: Up to 10 percent.
Exceptional Circumstances: For an extra-large or rush order, or if the cashier helps you to your car, tip 10 percent or more.
Things to Consider: If you’re a regular customer, tip the cashier well to ensure the timeliness and accuracy of your orders.