I try to tip those who help me wherever I go also.
At times I will only have a dollar or two in my wallet, but if someone is serving me, I will leave it on the table for their service.
If I don't have any cash on me for a tip, I will add it to my credit card total when I pay for the meal.
Be sure to always carry some kind of cash with you when you are checking into your room.
When you tip the luggage handler, he will tell his buddies. And when you need something else for your room, they will be tripping over themselves to get up there for the tip.
The same thing goes for tipping the maids.
A good friend told me, if you tip the maids every day and then need something during your stay, they will make that extra effort to help and then some.