A reed should not be chosen at the end of the day when tiredness of the mouth is present (muscles and nerves), but fifteen minutes after the beginning of practice.
It usually takes three to four days to adopt a new reed.
It is best to set aside 3 to 4 reeds of similar quality and use them interchangeably when practicing – for twenty minutes with each. You should mark each reed on the back with a pen in order to distinguish them.
You will find out which reed is the best in 3 to 4 days. Of course, for public appearances select the best ones.
We never choose the reed on the day of the event! The new reed is not reliable because it has not gone trough all test-controls described above. It can often fail and significantly reduce the quality of public appearances, and thereby destroy all the efforts made by a perfomer in order to learn the piece.