The best strategy is to start doing strengthening exercises for the feet before starting pointe classes.
One or two classes a week will not prepare the feet, or whole body for pointe work. Three classes a week for at least a year will enhance the preparation, but even then, to achieve the optimum strength for pointe work, there are exercises a student can do every day.
The dancers I talk to seem very motivated to get into a pointe class, so I am assuming that adding an exercise regimen to their already busy day would not be a problem.
Lisa Howell, author of The Perfect Pointe Book, explains many fine points of anatomy, especially of the foot structure and muscles. She covers turnout, hip placement, and more.
Students wonder "do I have the right arches for pointe?" ...."do I have the right toes, the right ankles, enough turnout?"...."why does my teacher say I'm not ready?"
I've always advocated holding a student back, if there is the slightest reservation in my mind about putting her on pointe. A child can improve ballet technique in any area, so why risk an injury or deviated growth pattern?
Concentration and awareness is extremely important in ballet class. It is recreational for many children, but there comes a time when dedication is required to ensure safety.
This dedication has to show up before pointe work begins.
Developing good technique in ballet, means pushing your physique to the max without sacrificing
safety. Preserving the integrity of the joints and muscles may mean a restraint of advancement. Fellow students who are a little older, more physically developed and stronger, may go into pointe class sooner than others who are not.
I've had students who are "born pros". When I've had to hold them back in some way, I explain exactly why and they really get it. They are willing to build strength for good dance technique, knowing that they will catch up once the strength has been established.
This attitude reflects a positive outlook and a visionary one. Children are more than capable of this. Whether or not they have a great talent, some have an instinct for the more productive approach to their progress. They are ready to suffer (and they do!) a short term disappointment.
It's truly difficult for a teacher to work out a long range plan for every individual student, to get them to build strength for future pointe work.
If a student can find a prepared series of assessments and exercises, and can assess her own progress, the ones who want to advance in this way, will.
The good news is, you can go and get what you need for your own strategy to get into ballet toe shoes!