Step 1
Choose a quality tee nut, a good quality one will be substantially larger than cheap chines crap for the same bolt dia

Fah King Chee Pwun on the left
Step 2
Press the tee nut into the ply for harder plies ( not I did not say hammer ) or screw in the tee nuts for softer plies using a bolt and a cawl whilst applying epoxy under the tee nut
Step 3
Screw in a 4 or 6 gauge security screw into one of the fold bays of the tee nut - epoxy that as well.

Tee nut security screwed into Australian Hoop Pine ( similar hardness to BB )
Step 4
When dried, run a thread tap through the tee nut to clear the thread of any gunk
I often attach the thread tap to the battery drill and run slow. Don't let the bit bottom

What a thread tap looks like for those that think it's a plumbing thingy