Calling all Creative Types

I said I was available to sub in Primary on Sundays, because now that I'm in my new ward, I'm kind of bored just going to Sunday School and Relief Society (I know, I shouldn't be bored, but I am). They took me up on my offer right away and I'm leading Primary music this week and next. It's been a while since I haven't been behind the piano.

I want to make a conducting poster. The idea is to sandwich the leg from a pair of tights between two pieces of decorated posterboard. I've seen one a that's a worm coming out of an apple and one that's an elephant's head with a trunk. The child who is helping puts her arm into the tight leg and waves the trunk or worm as she is conducting. I have some grey tights and a pattern for an elephant head. Any ideas about how to securely fasten the tights leg into the poster?

I would also like to make a singing thermometer (the temperature reading goes up as the children's singing improves). I made a lame, inadequate one once. If anyone knows of a good way to make an easy to use thermometer, please let me know. I would like one that the children can operate themselves.