I also crapped on painting handles for a long time, but my wife got me one for my birthday and I love it! I use this one though https://www.amazon.com/Painting-Miniautres-Compatible-Miniatures-Figurines/dp/B09DCMS1K5. I like that it has enough discs to hold a squad of 6 and just keep cycling through the models! To each their own though.
This is the tutorial I used for my necron blades, the video isn't very hight quality but the techniques he uses work really well.
For shaky hands I would recommend you get this painting handle, I've used it for a couple of months now and it works really well. It might not work well for larger models but it works well on smaller infantry models and characters. The metal bar is for resting your hand on while you paint so you don't shake as much.