Stamina
Stamina is something we all need as a dancer...in some cases mental/physiological stamina to get through hours and hours of rehearsals on end, or long performances day after day, but then there is the technical stamina, just do be able to do strenuous exercises. To work on stamina I've been devising exercises to do. I would recommend doing these exercises once a day--within about 2 weeks you should see improvement in your physical stamina (it was 2 weeks for me, at least). Since most dancers tend to get winded the most during allegro exercises, these are allegro exercises.

Eight sautes in first position, eight in second, eight changements, eight echappes saute batues (echappe beat-changes). Repeat with four jumps in each position, then two, then twice with one each.

Two changements, one echappe saute, and one soubresaut, right and left. Then repeat right and left with beats: Two royales, one echappe saute batue, and one entrechat. If you are really feeling adventurous, you can do entrechat six in place of royale.

Try them fairly slow first, then slowly up the tempo as it becomes easier. Good luck!