Sometimes the standard tips on woodworking glue caps dispense too much glue for precise situations, leaving a mess to clean up. I’ve found that caps from unlikely sources like mustard bottles or craft glues can offer a finer tip for better control when you need it. There actually are a lot of different caps that will fit 8- and 16-oz. glue bottles, so experiment to find the ones that suit your needs best. Keep them with your gluing supplies so they’re ready to thread on when just a tiny bit of glue will do.
– Jim Wilson
San Marcos, Texas