Hand printing with finger paint

A very simple yet engaging activity is hand printing. The way I have typically presented this activity is a squirt of finger paint on a tray. However, a mixture of liquid food coloring and flour would also do the trick. Make sure the food coloring doesn't stain permanently. From my experience, powder food coloring can be turned into liquid by adding water but the tinge stays in your skin for a while.
This time around I papered the table with brown craft paper, placed the tray with paint on one corner, printed a hand and left it there as an invitation to my toddler. That simple. I love leaving invitations here and there and specially watching my child approaching them.
How do you present this kind of activities? Do you let your children take the lead? I'd love to hear about you!