Ear equalizing techniques:

Valsalva vs. Frenzel methods of ear equalization: This video was recorded by Ted Harty for freedivers but trust me! It provides valuable information & tricks.
DAN USA's 6 methods to equalize your ears.

DAN USA's extensive review of your heart health vs. scuba diving.

The calf raises exercise.

Disinfecting dive gear:

Fitness to dive after COVID: