This is an issue that causes me angst. Tip or no tip?

Last year, I stayed at 40+ different properties with CLs. My experience is maybe 1/4 have tip jars/plates, etc. Another 1/4 has overt tipping on the desk or people leave it on the uncleared tables. The other 1/2 leave me feeling guilty if I don't leave a tip or awkward if I do leave a tip. I've had tips refused - one time by the best CL clerk ever - and felt like I've insulted some by giving them tips.

Sometimes I try to leave a tip on my bill - sometimes it's embarrassing to hand someone cash, and it's easier to get reimbursed if it's on the bill - and some hotels do this, others do not.

At Christmas time, if I'm staying in a hotel where I've gotten to know the CLA, I'll give a larger tip in a card. A few years ago, I stayed in one FS so much I actually purchased the CLA a Holiday gift. (No, not a Fancy Candy Basket, rather a monitor for a computer she had recently purchased and made an off-handed remark about it making her want a new screen, but she thought the prices would be lower after the holidays.)

It's nice to know this confusion is shared. Can anyone from MI tell us what is the correct protocol? Or is it a hotel-by-hotel issue?