Writers get to fill their books with broadcast and print ads, some outdoor and web stuff, and maybe a collateral piece or two. Account people don't have books to showcase their work, but if they did, they would fill them with Word documents and PowerPoint presentations. Not exactly the most scintillating material, it's a better cure for insomnia than anything else. But the reality is if you want to be a really good account person, you need to master writing a good letter of proposal.
There are some terrific books on how to write well, and I include three in a postscript at the book's end, but I also think it would be helpful to explain five things that I think are critical in putting together an effective proposal letter.
It's an agreement, not a contract. I may be parsing words, but if you allow the lawyers—yours and the client's—to get involved in drafting a contract, the assignment will be over before you sign anything, and the only one to profit will be the attorneys.
In all the years I've been in advertising, I have never needed help arriving at a client agreement. I've relied instead on a simple and thorough letter to establish an assignment's scope of work. Once I've completed the letter, I ask my client to sign it before beginning the assignment.
Letters of proposal do in fact operate as legal agreements, but by keeping the writing ...