One-sheets...

I’m currently preparing for a conference where I’ll be pitching to an agent and a publisher. However, I’m struggling to find resources on how to write an effective one-sheet. I’ve googled it, but google hasn’t been very helpful or reliable (it even said I should include a book cover 🤨). Any advice or resources would be so helpful! Also, are more visually appealing one-sheets more effective than regular ones? I know you should stand out, but I also know that agents and editors don’t always like it when you break the norm and they don’t always like “fancy”.

Thanks!!