You can leave the tip in several places. Also if you stay for a week, you should get to know your maid's name. That would make leaving her a tip especially easy. Then you could leave a card, thanking them for their service during your stay, with the tip in an envelope with their name on it. Thus insuring that the maid you want to receive your tip does and that they also have the personal touch of the note. Then you can leave the note under the glasses in the bathroom, or under the edge of the ever present lamp on the table. If all of that worries you as not obvious enough, you can tape it to the mirror in the bathroom or in the bedroom. It sounds like alot of work, but if you keep the small "thank you" notes with you, it's really very easy and quick and can brighten someones day.