Mistake proof nail art may be a slight exaggeration, but it's only a slight one. When I started out doing designs on my nails I made more of a mess of my nails then successes, and to clean any errors was so painstaking or I'd have to take the entire nail of polish off. This is a much easier method.
This is where the Shellac comes into play. To avoid having to take off your entire nail of art when you make a mistake, get a base of Shellac applied. This trick works because Shellac requires more then a bit of elbow grease to get off, (In fact they recommend you only have professionals remove it in salon) and you can change your art however often you like. I decided to get a dark purple colour on my nails, I did a gorgeous galaxy nail over the top, then removed that after a few days and applied some nail stamping with my MLS 301 plate.
Now you see it
Now you don't
Oh Hai ice-cream and lightning!
It's worth noting that glitter is even more of a pain to remove with this idea though, because you're still trying to remove it without damaging the Shellac underneath.