With needle tips, I find that using a straight pin as a stopper and storing the bottles upside down (as long as the glue is relatively thick and the needle is a good fit) is a huge help. (That was actually my first practical cut project, making a little upside-down-glue-bottle holder for my pegboard.)
Using straight pins as stoppers works for a while and then the pins rust and you have a mess. I have found that the nylony plasticy rings that hold tags unto garments work much longer - and no rust. Simply make a snip in the ring and straighten it out and you are ready to go.
It depends on the pin. Yes, some do rust, but I’ve got a few pins that I’ve been using this way for years, rust-free. Anyway, the point is that something inserted into the tip (vs. using a cap) is a good way to keep the needle tips clear – using tag fasteners is a good idea!
Whoa Nellie! Just tried one of these things and Man! Is that ever an improvement! Great suggestion! (The Fast Cap Babe Bot I was using positively sux in comparison. And tends to split so avoid it and save a couple of bucks.)
Followup: my glue bottle did actually clog after not using it for a little while. I took the cap off, then took the wire from a bread tie (solid, fairly rigid, and skinny) and pushed it through the tip. Glue was fine after that.
I also am starting to ensure that the tip is clear of glue before I put everything away, I squeeze air through the tip and get it as empty as possible. That might be why it was so easy for me to clean, I dunno.