A My Block is a combination of one or more blocks that are grouped into a single block. Once a My Block is created, you can use it in multiple programs.
From: LEGO® Mindstorms EV3 Information
It's like defining an external function, but with blocks, and makes for great program shorteners (instead of having 20 or so blocks, 2 or three times, the students learn to make one single My Block, 2 or three times).
However, the students seem to be forgetting, repeatedly, that this tool exists. Only when I point out "why not use a My Block, instead of copy-pasting a lot of blocks?", do they use the My Block tool.
I'd like them to understand when they should use My Block, (and hopefully why, because it might give them insight on external functions later on, should they choose to study CS) without having me point out the tool. There are many use cases for My Block, so giving them a list of situations doesn't work (I've tried, to incredible failure).
What can I do to help the team members understand when they can and should use My Block?