It's possible that using high quality templates in your project to give it visual interest might make your project more "engaging" for your stakeholders, giving you a competitive advantage. Templates can raise the perceived professionalism of your project: The same way that a suit might make you appear more professional when going on a job interview, the use of project templates can make your project appear more professional.
Okay, now you've written the proposal. The finish line is in sight, but you're still not quite done. Take some time to make your proposal visually appealing. You might want to incorporate your company logo, use colored borders, or employ special bullet points and fonts. Just make sure that any added graphic touches match your style and the tone of your proposal. Don't forget to spell_check and proofread every page. For the final check, it's a good idea to recruit a proofreader who hasn't read your proposal before. It's way too easy to miss errors in your own work.