A little can of guide coat powder and a long board sanding board will help find those little mistakes. Filling in those little dents and valleys is a though thing for those with little practice at body work. Guide coat will help you see those little valleys and peaks, and a long board will give you the tools to help you smooth them out. With the board held straight use and X sanding motion with the long board will help.
Yes don't you just hate fixing that little dent turns into a football field by the time its fixed ,
That's why I'm sending out my hood to a body shop rather pay someone to fix it for $125. than mess with it my self