Beginner here!

[livingkennedy]

A good rule of thumb is not to offer unsolicited workout advice to anyone you wouldn't remind to examine their zipper.

[JerekKruger]

Having received unsolicited workout advice I'd say good advice is simply not to give it.

[SMOGGY]

I suppose don't give it unless it's asked for.

[Dangerscouse]

Yep, I never give advice. That's for the PT to do. I'd be more than happy to help if someone asked for help though

[kerosene]

I think this is a great video for technique. I would take the overlapping of legs, back & arms with grain of salt as it is easier for beginners to keep track of stroke elements when they are more defined.
The stuff on catch is great though.