G = Grammar. Grammar is merely a tool to help you make your meaning clearer. Style guides such as Lynne Truss's Eats, Shoots and Leaves are a great source of information but, if grammar is a weak point, remember just get the story down first. Find a trusted friend who likes their grammar and ask them to vet your story before you send it anywhere. Writing groups (as long as they are sympathetic to the fact all writers struggle with grammar at times) can also be useful here.
H = Heroes/Heroines. They have to be fully developed characters and not "puppets". They have to have off days the way the rest of us do. Yet there should be something in their character that makes it obvious yes they are the heroic characters and deserve to be. What is special about them? What is the heroism they are renowned for already? What situations will being out the best in them?