Creating a sell sheet
A sell sheet is a single page that sells your game to a publisher at a glance. It is the tabletop equivalent of a resume, and for most publishers it is the first and often only thing they will look at. The goal is not to explain the rules. The goal is to make an acquisitions person say "send me the prototype."
The standard contents are consistent across the industry. Title and a strong tagline. Player count, play time, and target age. A one-sentence hook that says what makes the game different. Three to five bullet points covering the core gameplay and what is novel about it. A photo or mockup of the game on the table, because publishers want to imagine the product. Your name and contact information. Some designers add a component list and a QR code linking to a rules video. All of that fits on one page, usually landscape, with more image than text.
The most common failure is treating the sell sheet like a rules summary. Publishers do not care yet how turns resolve. They care about the hook, the audience, and whether the game fills a hole in their line. "A 30-minute bluffing game for 4 to 8 players where the traitor deals the cards" tells a publisher more than three paragraphs of setup instructions. Lead with the experience, not the procedure.
Design quality matters more than designers expect. A sell sheet with clip art and cramped text signals an amateur, fairly or not. You do not need final game art, but you do need clean layout, readable type, and one good photo of the prototype. If graphic design is not your skill, this one page is a worthwhice place to spend a small amount of money on a freelancer, typically far less than commissioning game art.
Video tutorials
71 Ways to Become a Better Game Designer
Board Game Design: Sell Sheets - when and how to use them.