Another neat and simple trick it to have the first target in the Makefile print out a helpful message that tells the reader what the project is and how to use it. One of those things that is useful both when you are working on the project and when you later return to it, years later.
I use this pattern for my makefiles. First item is for "help", and it dynamically scrapes all the other commands (assuming format : ## ). So if I do 'make help' it'll list all the commands in the makefile without much extra work from me.
