Even when woodwind instruments are used carefully, the keys can become distorted and air can leak. Even the slightest bit of air leakage can make the whole instrument difficult to sound. If one student play the same instrument all the time, the student may not notice this. So take the time to occasionally play the instruments of other student in the same section and check for key deformation and the sound of the instrument.
Students can also check the instrument by playing the lowest note of the instrument once a day, or by playing all the notes in a chromatic scale. For this reason, it is important to memorize all the fingerings for the standard range, regardless of the piece you are currently practicing.
Even during practice, if students occasionally (if there are water droplets inside the tube) use a swab to remove the moisture from inside the instrument (for flutes, wrap gauze around a cleaning stick) students can keep the instrument in good condition for a longer period of time. Keep the swab hanging on the music stand during practice so that it is always available.
For clarinets and saxophones, always put on the mouthpiece cap during breaks or when moving with the instrument to avoid damaging the reeds. For oboes and bassoons, remove the reeds from the instrument and put them in the case.
Do not apply grease to the joints of the flute.