Grant writing is a game. You need to understand the rules (written or unwritten). This is my somewhat arbitrary list of them:

#1: Show excitement. If you are not excited, the reviewers will not be either. This is the most important rule. 1/10

#2: Significance means how your work will advance the field. It does not mean your work has to cure all cancers. It almost certainly will not, but it can still have high impact. 2/10

#3: You have to establish feasibility in the Approach section. This is a chicken and egg problem. If it is 100% feasible, it may be boring. If it is super exciting, it may not be feasible. Try to find a balance. 3/10

#4: Reviewers decide based on the big picture. If you made a convincing case that your study will have a high impact, most reviewers are willing to overlook small problems in the details. Some details are more important than others however. 4/10

#5: Always customize the Personal Statement in your Biosketch to the grant you are writing. Explain briefly why you are the right person to do this particular work. 5/10

#6: Use the Facilities page to make a case why you institution is a great place for your studies. List collaborators, experts, core facilities, even if not directly relevant to your proposal. This is especially important if you are not at a tier 1 university. 6/10

#7: Send your Specific aims page and Significance section to a colleague who is not on your close field at least 2-3 weeks before the deadline. If they do not understand it, or do not find it exciting, rewrite them. 7/10

#8: When you revise a grant or try to renew, the reviewers do not see the previous version. What they see is the previous summary statement, that includes the abstract. Keep this in mind when you write the grant. 8/10

#9: Just because you responded to all comments does not mean you will get a better score. Sounds cruel, but this is how it is. Go beyond what is requested in the revised version to make your grant more compelling and to show progress. 9/10

#10: If you do not get a good score, or get triaged, do not despair. Keep submitting and resubmitting. Persistence is the most important factor on the long run. 10/10