I first made a set of group work sticks for the fall 2014 semester. I have used them in almost every single class since. My students all know, walk into class and grab a stick.
I decided last year to make a set of forty that continuously got students into groups of five, instead of different sized groups like the first set. Now that I am teaching at the local high schools (through a program at the community college I work for) I have smaller class sizes.
I can always pull sticks out, and it's easy to quickly remove a couple colors worth. However, its a pain to shuffle through the pile trying to find a bunch of smiley face sticks or something because I was going to use symbols as a grouping mechanism that day.
So I made a set of thirty...which meant fresh new colors...and lots of painting and stamping.
I would have never guessed that popsicle sticks could be a key tool in teaching at the college level, but they have been for me.