What is a good "tune up" to perform on new AR mags? I know I've read one thing or the other one place or the other, but thought someone could provide a synopsis of the suggested techniques. Thank you in advance

This is what I do to test a new magazine.

Check to see that the empty magazine locks into a lower and drops free.
Use a ruler to push the follower down and check for binding.
Fully load the magazine, use a LULA to unload the magazine.
Fully load the magazine and let it sit loaded for at least 30 days.
At the range see if the loaded magazine still drops free.
Fire the 30 rounds, bolt must lock back, and mag must drop free.
Load and fire 5 rounds, then 2 rounds then 1 round, bolt must lock back every time.

After that I consider the magazine reliable and put it in storage.

Gary