There are a few steps you can take after you receive the disappointing news.
First, request a copy of the reviewers’ score sheets and comments. See what they liked and didn’t like about your proposal.
Second, find the list of funded projects; request or download copies of the winning proposals from organizations similar to yours. Many federal departments post the proposals on their websites. If not, go back to the Notice of Funding Opportunity and look up the agency contact person to request copies. They’re public documents; it’s not a big deal to ask.
And finally, once you have your scores/comments and a successful application or two in hand, start the planning process for the next round of funding. Don’t wait until the next opportunity presents itself. Get to work while the ideas are still fresh in your mind.