Like the Quintuplets, there doesn't seem to be a standard way to count out Sextuplets.
You can use straight counting
You can use an Indian type of method
You can even use a doubled triplet type of counting
Download the midi file. Size: 19.2k
Hear the exercises played at 65 bpm. Time 8:48
The single beat basics.
Polyrhythms and rhythm clusters.
Always use a metronome when practicing the exercises.