Does your trombone section have an airy sound? Have you checked the water key corks? It is such a simple thing that makes a drastic difference in the sound. Try using self adhesive neoprene water key corks. They are easy to install, cover the opening completely, and will last a long time.
Does your clarinet wobble at the center tenon where the upper and lower joints meet? It probably needs a new tenon cork. if you don’t have any on hand, use unwaxed dental floss to wind around the existing cork to make the connection snug again. The great thing is that you can add as much or as little as you need to secure the joint.
Has your flute completely stopped making sound? Check out the trill key springs. Located at the top of the body section, it is easy to catch these springs on clothing, music, stands, or jewelry. Simply take a spring hook and place the spring back into the cradle at its correct resting place and you’ll be making beautiful music again.