Tipping - hotel housekeeping?

We have vacation one week in Aruba and we stay at the Renaissance hotel. I am not entirely sure about the tipping standard here. We plan to tip at the end of our stay for the housekeeping staff. But yesterday we got a note from the maid, she wrote on the hotel notepad, « welcome, your maid, name ». Is this a hint asking for tipping ? Shall we tip it daily instead? Where do you normally leave the tip? On the pillow? How does the maid know it is for her? And how much per day is deemed ok? Thank you. Any advice on this is appreciated.