Check out your instrument each time you play for changes in its appearance or play ability. It may indicate a repair that needs to be done.
Avoid extremes in temperature and humidity. Allow the instrument to warm up to room temp. before you play it.
Have small repairs done often. Neglected repairs become large, expensive repairs.
Wash mouthpieces once a week at minimum and always wipe fingerprints from the surface to avoid tarnishing the finish. Take reeds off mouthpieces every time you are done playing.
Lubricate with cork grease, oil, cream where appropriate.
Have appropriate accessories for your instrument care.
Extra reeds available at all times (clarinets and saxophones).
Cleaning rods or swabs (flutes, clarinets, saxophones).
Valve and slide oil and grease for slides (brass instruments).
Percussion players should always have own sticks, mallets, and carrying case.
Sticks for snare drum.
Mallets for bells and timpani.
Triangle beater
Own accessories as you develop (tambourine, wood block, triangle, cabassa, etc.)