The "Grant Response Amateurism, Vexation, and Exasperation (GRAVE) Gage" that Mr. Le gives us is so, so great. Definitely give this a careful read if you are new to fundraising or grantseeking. It will explain some grantmaker practices that may seem mysterious to you (such as why a funder might have a persnickety requirement that you submit one copy of your proposal unstapled).
Reading the grant guidelines and following them to the T: this is essential. It's also pretty easy.
Writing a grant proposal is like following a recipe. As long as you have adequate kitchen skills and the right tools and ingredients, you will be able to create a passable concoction.
The hard part is communicating with funders outside of the prescribed format of the proposal.
Long-term, sustainable success in grantseeking depends on professional, thoughtful communication with your nonprofit's universe of funders -- whether your grant is awarded or not, and whether the project is going smoothly or not. It's especially important to go the extra mile to demonstrate the impact of a grant.
The GRAVE Gage gives us some sage advice about the nuances of communicating with funders -- giving them credit in the press, sending appropriate emails to program officers, and letting them know when things are going a little off the rails.