Start with the material, not with a blank page. Attach the previous offer as PowerPoint or PDF, the price list as Excel and the brochure as PDF, and say who the new deck is for. The AI reads PDF, Word, Excel, PowerPoint, images and text files of up to 30 MB each, plus up to three public links per request, for example your website. For a bank meeting, attach the figures: it reads the values of every sheet in an Excel file.
The brief carries the decision. “An offer for a dental practice, 8 slides, ending on three package prices and the next step” gives the AI something to build. “Make an offer” does not. Name the audience, the goal and the structure you want; the pages on the sales deck and the business plan show structures that work.
Before building, the AI asks up to four questions, but only where your brief leaves gaps, and shows a page plan: one card per page and a list headed “What I assumed”. The plan is where you catch a wrong assumption cheaply, for example a price you never gave. Then it builds the pages one after another and checks each for cut-off text, weak contrast and broken images. The plan comes first; a finished deck usually takes a few minutes.
Check every number yourself. The AI is told not to invent figures and to label its assumptions. The closing chat message names the assumptions it made. For a bank or a partner, read it before you read the slides.