If a tube springs a leak along its side, you can save it by wrapping it in heavy-duty aluminum foil. When you’re making such a mess with it that you want to pitch the whole thing, go get a new tube.
If you have lost or broken caps, you can again use foil to keep the paint from setting up in the tube. In the end, you may have to throw it away. Whenever you discard a tube of paint, keep the cap for these types of problems.
Keep the openings of the tubes clean. Wipe them off with a paper towel to keep hard, dried paint from gumming up the threads of the screw top. Clean out the lid in the same way so that it fits back on tightly. Keep a set of pliers in your paint box for paint tubes that are difficult to open. That should keep you from twisting the tube so much that the tube breaks from the stress.
One last thing, and maybe it goes without saying: Never use your teeth to open a tube of paint!
