I did a DSD course as a taster for scuba, since it was a lot cheaper than doing the OWD and I wasn't sure if I'd like it or not. During that course, I was working with an instructor on a one-to-one basis, both in the pool and at the dive site. Before I was allowed to get wet, we went through a few ways of equalizing and I was advised to try them until I found the one which worked best for me and then stick to it. We also went through the whole 'never hold your breath' thing, along with detailed explanations of what would happen if I did.
The instructor took me into the pool to learn how to clear the mask and purge the regulator (the mask took me a few tries, but he was very patient and laid-back, and I was never out of my depth in the pool, which made a big difference). We then went through equalizing and not holding my breath again, and told me in detail where we were going to go and what we were going to do. After that we went out on a RIB to the Mole dive site (about 5m; I found out later it's where they take all the DSD and OWD students) and I was taught how to do a backroll entry which was first demonstrated by the instructor; the boat captain, himself a PADI professional, made sure to step on my fins to stop me going in until he was satisfied I had my hands in the right places and could go in safely and that I knew where to swim to afterward.
The instructor repeated what he'd said before, about using the rope to pull ourselves down, equalizing as we went, then we headed under. During that time, he stuck very close to me, often checking if I was okay. After a bad sporting accident as a child, I'm very cautious when it comes to my own health, yet even as a complete novice, I felt 100% safe underwater and signed straight up for my OWD course as soon as I got back to the dive center.
About the only negative thing I would say is that he had a habit of grabbing me by the shoulder to point out interesting shoals of fish. Not dangerous, but it was a little unnerving to have a hand suddenly pounce on me without warning every so often
