Hi, a few things I'm trying to improve and could use some help on

1. I keep making silly mistakes when solving a problem. Just simply things like trying to iterate over an array and not using the array length and instead listing just the array. This is purely accidental and me just not paying enough attention. Even when I try I regularly make these mistakes.
2. I always forget about edges cases

Does any one have a step by step process they can recommend that I can try to follow? thanks