As mentioned above the most important thing to do is to have someone video you while you are practicing skills. I had my wife video me 3 times a week for 6 months when I was practicing skills. There is no better way to learn than seeing what mistakes you are making and what you are doing correctly. Watching the videos is humbling but helps you visualize what you need to do, so you can go over it in your head, (self visualization).
My instructor had me start by maintaining buoyancy (+- 2ft.) just above the bottom and removing first my decompression tank and place in on the bottom, then the left tank and placing it on the bottom, then my right tank and extending the long hose and placing that tank on the bottom, while maintaining buoyancy (+- 2 ft.) without any tanks breathing off of the long hose, and then putting everything back on in reverse order all while remaining within the (+- 2 ft.).
I found that by practicing maintaining buoyancy +-2ft. without fins really helped build those "neurogenic pathways" that make balance and buoyancy automatic.
In my class we used a lift bag and a reel, shot at 80 feet, not a DSMB. Definitely takes some practice to get it right and requires a one handed gas switch for deco.
Good luck and practice practice practice!