There are often 3 classes:- sweet mead, dry mead, honey wines(including metheglin, cyser, etc)
Make sure your entry is in the right class – often the boundary is set by use of a hydrometer and at about 1,125
Keep the air out of your preparations so that no acetic acid (vinegar flavour/smell) is formed.
Be prepared to wait a long time for your wines to mature – some take years, so do sample tastings before you pick the ones for the show. I keep mine in plastic bottles (coke, lemonade etc) which do not impart any taste or smell and can have all the air squeezed out before sealing. They are also safer to store as they do not explode or break when dropped. Also, you can fill a 75 cl wine bottle from a 2 l plastic without disturbing the sediment.
For the show have correct bottles – 750 ml clear glass wine bottles with shoulders, Bordeaux style, and a good punt in the base. You may have to buy some wine and drink it just to get the right bottles!
Fill to within about 1cm of the cork, which nearly always has to have a white plastic top so that the judge can remove it easily and replace it. Don’t put normal wine corks into a show.
Filter your mead just before the show, with minimum exposure to air, so there is no sediment and not floaters. Wash the outside of the filter paper first in case there is fluff stuck to it. Coffee filter papers do a good job.