We continue to use plastic sleeves with the safety pin style of nametags. They are very inexpensive at Sam's Club.
We use the nametag's safety pin to fasten to a colored shoelace which the kids have put a variety of beads: # in family; # pets; # places lived; 1 for ea grade in school; sports/activities/instruments they play pr enjoy,etc.
I print nametags each fall (and new folks can be added easily by the next week) on bright paper and some visitors ones for each group.
We have 3 WoRM classes- Yellow (K/1) Red (2/3) and Blue (4/5/6)
We had a great crafter make a rainbow board where our workshops names and grade group assignments are velcroed up. This board also has hooks where the kids (often need reminding) come by, see where they will be going today, pick up or drop off their nametag.
Within the 1st year, everyone is used to using that stairwell and checking it and leaving their nametags too!
We would often put candy treats or coupons for a free cookie in fellowship hall ON THE BOARD AFTER the lesson to help the kids stay in the habit of "checking the board" and leaving their nametags.