Here are some basic, yet crucial tips for writing winning recipes, that will work for most any recipe contest you'd wish to enter.
First, when writing your recipe, be sure to use the exact ingredients, with their correct names, that the sponsors may be asking for. For example, if the contest asks for a sweet potato as the main ingredient, be sure not to mistake these for yams, as these two can, and will at times, be mistaken for one another.
Secondly, use the exact measurements of each ingredient. You will want to use "1/4 cup oatmeal", as opposed to "a handful of oatmeal".
Third, make the recipe neat in its layout. This can help with the ease of passing through the contest in its various phases, and makes it easy for judges to quickly skim through and get an initial idea of what the end creation will be.
Finally, make sure to, yes, once again, read through the official rules, and while doing so, pick out the subtle innuendos of what they may be looking for in it. These things may give you an edge, as most contests are searching for something done in a particular fashion that suits their advertising and creative needs, which are often "clued" to us in the rules even more so than in the name of the sweeptakes, along with this being where you would find the standard judging criteria for each particular contest.