tips are optional. Don't feel at all obligated. I have cleaned houses for years. I receive gifts in the way of unwanted things, food/meals, an occassional gift for my birthday, holidays, etc. My clients have become my friends so I get more sometimes than someone hired from a service in the way of the above mentioned "tips"
Thanks everyone for sharing your experiences. Keeping your advice in mind, I had a candid conversation with the service owner. He told me in no uncertain terms that tips are rarely given. He said their turnover rate is low because his staff are paid well and they don’t rely on tips. I plan to make a note of my team’s birthdays and also to remember them at the holiday season. Thanks again!