When I was asked what publishers could do to help their entries, at first I thought that I didn't really have anything to offer. In retrospect, that isn't quite true.
I've talked about some of this stuff before, but bear with me as I try to collect my thoughts into one place. These are only really things that apply to me, and may not be overly useful depending on the tastes of whoever judges next year, but they may be of some value, so I'll offer what I have.
First and foremost, don't wait until May. I received about half of the entries within the last month or so of judging, and I'd be lying if I didn't say that some stuff started to bleed together in the final push. Early on in the process it was easy to take a day off or set something aside so I could cleanse my pallet, but in those later days I just had to muscle through things, and it's likely not a coincidence that many of the things I really fell in love with came in the first couple months of submissions. Early on you have time to research things, get a feel for them, read about the experiences of others... That gives you a chance to see what a game has to offer even if it isn't precisely your own tastes. At the end of the process you're lucky to have time to read the book and maybe a couple reviews. I know it's tempting to gather things together in one big shipment, and I'm sure it saves money that a lot of publishers simply can't waste, but I really can't stress the importance of getting your products out as soon as possible enough. It'll help you, and it'll lighten the load on those who come after you.
Also, if possible, think about letting the judges know what categories you think you might deserve. I know you turn your entries in to the board, but the judges see very little of that, and while the board does make it available, it's not always handy right when we're reading through the book. I know it might be time-consuming, and you simply may not be able to, but consider a letter of introduction. I received one or two, and I have to tell you, it's nice. Let the judges know what you think is cool about your product. Don't be shy about pointing out specific pictures you'd like them to consider in detail, or some neat mechanic that really enhances the feel of your game. A paragraph or two would be more than enough, and it could go a long ways toward getting a judge excited about the product before he or she ever cracks the cover.
Also, don't be afraid to communicate with judges, but make sure to keep it public. I was extremely pleased to see so much publisher/writer participation in my blog and the threads I post to on various forums, but you always get a little nervous about private emails or IMs. I received a couple of very generous (and well-intentioned) offers of materials to help my judgments, ranging from questions answered by authors right down to PDF copies of the entries or the core books of their line (if they weren't submitted) to make my life easier. These were actually appreciated, but I didn't think it would be right to accept any offer made in private, so I turned them down. The one that was offered to all judges, and in a public forum, I accepted, and I'm glad I did, because the PDF in question really enhanced my understanding of the materials in the entry.
I don't really believe that there's anyone out there who would actually stoop to attempted bribery, but it's not my beliefs that matter. It's all about the appearance of propriety.
That said, don't let worry about baseless accusations keep you away either. Feel free to answer questions, or ask them yourself. Offer up a link or two to reviews that you think represent your product well, or maybe even an actual play post. If the judges think you're overstepping, I'm sure they'll let you know, but never be afraid to make someone's job easier. If there's not a blog or something like mine available next year, it might be a good idea for interested parties (fans as well as publishers and writers) to go to ENWorld and start a thread. That's where the judges deliberate, and I'm sure that they'll pop in if you let them know it's there.
Oh, and don't forget to let the judges know what you intend to submit if you're not going to be able to send it in right away. Sometimes the judges may already own a copy, or might be willing to look into doing a little advanced research at any rate. If one of the judges happens to be a reviewer that you trust, feel free to send them a copy to review ahead of time. Remember that publishers are not required to send a second copy out to a judge for review if they've already been comped a copy.
I guess that's about all I have to offer for now. I know Stuart and Liz check this blog, and strongly suspect the Kevin, Jeff, and Denise do as well, so perhaps they could add to what I have here if they get a chance. I'm sure it'll be different for everyone, and what I have to offer may not help at all, but I'm certain that it couldn't hurt.