If doing nails had one by one steps (instructions)...
The most important step is being able to "see", then the second would be to have a "vision" (very closely connected).
Being able to see well, discounts a very basic excuse for doing poor nails.
The amount of times I have heard the excuse "but my light was bad, I couldn't see properly".
Get a good lamp and a good bulb (always have a spare bulb on hand).