What should be in a grant proposal to strengthen our chances of success?

We apply for grants fairly regularly and our success rate honestly isn’t great — maybe one in five. I know our work is good but I feel like our proposals aren’t doing it justice or we’re missing something funders are looking for. Is there a structure or checklist for what a strong proposal should include? I’ve read various guides online but they’re very generic. I’m particularly interested in what Caribbean and T&T funders want to see — what actually makes them say yes.