How to convince the grant commission?
Grant commissions meet a few times a year (e.g. every 3, 4, or 6 months) to decide which projects to fund. Commissions consist of reviewers and representatives of the funding body. Usually they have a lot to discuss, so for postdoc-sized grants they probably will spend 15' or less per application during the meeting.
Commission members often read only the summary of an application. To make your application appealing and the work of the commission easier, you need to provide a short and simple message. Summarize your entire project in the first sentence of your summary - and make it interesting! Make it clear what problem you address and offer a solution. An interesting CV that fits to the application is a strong argument as well and helps you to stand out of the crowd.
The best thing that can happen to you is if your reviewers are so convinced that they become advocates of your application in the commission meeting. In contrast to common lore it is not necessary to know panel members, have a lot of publications or provide excruciating detail. The key is to use the limited time and space you have to communicate one simple message that explains why your project matters.