Here's a series of short How-To-Videos demonstrating important basic Scuba skills.
How To: Overview https://youtu.be/kYATdTip3ZA
How To: Clear Mask https://youtu.be/KqxxwWCG1yY
How To: Regulator Recovery https://youtu.be/xYa9ZpfAA3o
How To: Giant Stride https://youtu.be/AxP121Ru4VQ
How To: Equalize https://youtu.be/wlBi1giT46k
How To: Gear Assembly https://youtu.be/YE2_K7WfarA
How To: Alternate Air Source https://youtu.be/zdno5ydkLWM