I use my trusty Klein 1005 crimp pliers. The team uses the Channellock version. You can get both at the big orange box.
I'd like to get the team a few DN-CT ratchet crimpers from Automation Direct, that's what we use in my panel shop doing industrial control panels. Does end sleeves too which are great for wagos.
Quality terminals go a long way though. T&B sta-kons, Molex/ETC, AMP, Panduit, 3M. Stay away from auto store terminals. The stuff automation direct sells is ok but its not great.
Make sure the kids are orienting the crimps right. I see a lot crimp them sideways and they blow the seam out. Bigger problem with the pliers type crimpers. If you use the uninsulated type with unisulated dies the nub should crimp oposite the seam.
If it does this you did it wrong.

Customer wanted to know why one of their outlets was on fire.
