One tip I can give is that editors like simple sentences (avoid compound sentences) as it's easier for the client to read, and make sure that you give a comment on all "no" questions. It's best to try to write concise sentences in chronological order, telling a story, but avoid flowery adjectives and keep it simple.
Do you have a spell-checker? I use Google Chrome as my browser and it underlines misspelled words in red when I make typos.
Don't worry about getting a 7 score. That should not stop you from getting more shops and you will still get paid. Just keep at it and you will get the hang of it!