Only preview successful applications from grantseekers whose projects are similar to yours. You'll not only get some good ideas, but an understanding of the competition too. Try to get program officials to review a 3-5 page summary of your plan first, to make sure you're on the right track. Don't overlook marketing. Make sure your organization will appeal to a potential funder, try to look professional, and involve key community figures where possible.
Management is vital.
You must be able to demonstrate that you have the management skills and experience that can deliver success. Know the funder. Don't ask for hidden agendas, but find out about general trends or new ideas the funder is currently interested in. Always work to a timetable. If you don't have tie to do it properly, don't compete for the grant at all.