I've been looking for a palm organiser for a while but the only ones I could find online cost £70 so I came to my senses and decided to make one.
Using your palm for reference draw out a rectangle template on to a piece of paper. Add an extra inch and each side of the palm. Make smaller rectangle, only an inch wide, at each side of the first rectangle. And then draw two more rectangles, the same size as the first one, at either side of the smaller ones.