I enjoy sprinkling non-fiction reads with my fiction entertainment. Try to keep the brain cells engaged even in summer. Steve Dublanica's Keep the Change is hilarious and definitely opened up a whole other economic world to me.
Having never depended on tips to pay my bills, I nonetheless try to tip waiters, waitresses, hairdressers decently. I expect a certain level of service and if received, I'll tip accordingly.
Dublanica interviews everyone in every job that lives off tips and his discoveries are eye opening. Strippers, shoeshine men, bathroom attendants, furniture delivery people - there are often many levels of service and everyone gets a piece of the dollar.
His trip to Vegas is worth the read. The levels of tipping for poker/blackjack/all tables is amazing. Plus there's a new language. Bad tippers are stiffs or fleas. Good tippers are called George and the highest level is King George.
Keep the Change will give you a new appreciation for various jobs and you'll reassess your own expectations as well as tip calculations. P. 275: Steve Dublanica quotes E.M Forster "Only connect! Only connect the prose and the passion, and both will be exalted, and human love will be seen at its height. Live in fragments no longer." Tipping helps you connect with people, if only for a short while.
Here's a tip - check out this book. Learn and laugh at the same time.