I agree that an Ohm meter can be a very handy tool. Always good to have a separate tool for verification. You can get the more expensive ones that allow you to fire the coil, or just a simple cheap one that only reads the resistance of the coil that will also identify any shorts. I use some cheap generic one that runs off of AA batteries.
You also have to be careful when tightening down your posts with multi stranded coils such as claptons. Too tight and one strand can cut right through another. Tighten down enough so that the coil does not move
With any coil, especially premade ones, there will always be a variance between what is advertised, what your mod reads and what is the actual resistance of the coil. Given how easy it is to build on the Drop RDA, mount 1 coil only, place it on your mod and see what the resistance is. Adding an identical second coil in parallel will half that resistance which should give you and good idea if your mod is ample enough to handle your projected build.
I always count the trimmings that I cut off to ensure one is not left behind inside the deck or found its way to the floor. Nothing worse than having a piece of metal in your foot, or if you have pets and sprogs (little people sometimes referred to as children)