A lot of the next advice will be about perception of how the drink will taste before the drink hits the judges’ mouths. A drink prepared with grace and elegance will be a better experience than the same drink prepared in an awkward way. This includes technique, preparedness, confidence, and knowledge about the ingredients. Also, look like you enjoy bartending and being there. It is usually not just about the ounces and dashes otherwise it would be a web- or email-based competition.
Come to the bar or stage prepared. Have everything on the tray that you need. Before the event, make sure what will be available to you. Do you need to bring all or just some of the ingredients? What tools and glassware will be there, and do consider bringing your own. Think of it as an off-site event that you need to cater. If it is a new bar location, ask questions to the bar manager where cubed and crushed ice are, where glasses you might need are kept (and if there is a chilled stash), etc. Make set up time as quick as possible and looking as organized as possible. Unscrew and uncork; perhaps have speed pourers already in the bottles. Lay everything out on an attractive towel, mat, or tray. If there are not chilled glasses, fill them with ice and water. Even if they are not perfectly chilled by go time, the intent will be noted.
Keep things tidy. Spills and drops happen. Bring a neat hand towel or two to clean up the station when setting up (many contestants abandon the station after their round and can leave a bit of a mess) and have it handy to clean up drips on jiggers, shaker tins, and bar tops. Pride of workspace and attention to detail help to prepare the judges to think that the same level of detail will go into the drink balance and will believe that it will taste better. Indeed, hygiene is crucial to food service. Also, if you consider muddling, think about where you will put your dirty muddler. If you use a tasting straw, think about where you will put it (and not throw it on the ground).
Have a story to connect to the judges in advance. Why you like the sponsored ingredient but also why each ingredient complements that sponsor and/or why you relate to it. Show the bottles to bring the judges into the process, otherwise it is just a blur of mechanics to get the drink in the glass. Also figure out who your judges are. If that is known in advance, you can cater to their preferences and their hatreds. If last minute, figure out whether they are a brand suit, bartender, journalist, or chef.
Talk while you work. Not always the easiest thing to do, but it will make that often 5 minute window seem like a pleasant wait for the judges before tasting the drink and not just a delay of them getting up to visit the bathroom they so desperately need to use.
Obviously plan out a drink that features the sponsor in a good light by making the ingredient prominent and tasty. However, this goes beyond flavor. What about the name and the story? In one rum competition, I was told that I had the best drink by far but the other contestant was more marketable on a national level. Here in Boston, making reference to the Daiquiri Time Out and the political incidents on Martha’s Vineyard is normal, but naming a drink after the gardens off of Martha’s and making a connection was enough to make a dark shadow for a conservative liquor brand (see figure 1: the Mytoi Gardens). Likewise, do not say anything negative even if you think a story about the frustrating people at the your bar is part of why you developed a recipe.
Also, when planning out your recipe, re-read the rules several times. Is there a cap to the number of ingredients? Are infusions or house syrups allowed? Are any of your ingredients from the sponsor’s arch rival? Can any of them be swapped for ingredients under the sponsor’s umbrella. What about maximum and minimum amounts of the sponsor, total alcohol, final volume, etc.? Will the winning recipe be promoted at other bars? If so, a house infusion or syrup or an obscure ingredient like Amer Picon might make the judges shy a way.
Are any of the ingredients you are thinking of using a major allergen or dietary restriction? If you are dead set on orgeat, ask your judges as you are about to prepare your drink if any of them are allergic to nuts. Even if you asked the event promoter in advance, it shows a good deal of sincere hospitality. Similarly, bacon fat-washed might sound tasty unless your judge is a vegetarian or religiously avoidant. Getting the drink into their belly and not pushed aside (or getting them sick or upset) will only help your cause.
Is there a time cap? It was painful watching the Bacardi competition and seeing contestants talk for a few minutes before setting to work with only a fraction of their 5 minute allotment left. All of the apologies in the world will make you and the judges feel better, but it may end up with your drink disqualified for being incomplete. Or made less perfectly due to the rush.
Take BarSmarts or read lots of Hess, Degroff, and others. Know when to shake and when to stir. If you are altering from the norm, mention why. Knowing how to stir and shake well will instill confidence. Fine straining is great for shaken drinks. Do bring or borrow attractive tools (even if house tools are available).
Garnish is always a great touch and should be prepped in advance with all of the cuts made and stuck on a pick already (if you are using one). The less handling of the items in front of the judges that you do, the better. The bartender is part of the drink, but less of the bartender's physicality should enter into the equation.
Practice what you will say and what you will do. From set up to clean up. A confident bartender makes it seem like it is not their first rodeo even if it is their first competition or first time behind that work space.
Remember, it is a combination of recipe, performance, and emotional connection in many cases. Frequently, the best recipe will not win. All too often, I will get emailed recipes from a PR agency and I will not want to make the winning drink. In fact, if I do make a drink from that collection, it was from someone who did not even place. I am usually surprised when I make the winning drink at home from the collection of recipes.
Finally, network. Sure, the judges are important for reasons that I do not need to mention, but the other contestants can become friends for life. Be pleasant to them. Help them. Speak highly of them. Negativity will reflect badly on you more than them sometimes. And positive energy will often be returned throughout the night and onward. Definitely go visit their bars in the next few weeks. Friend them on Facebook. You all shared something special and powerful together so make good mileage of that bond.
Do thank the judges afterwards. Be open to what they have to say. Feel free to ask them questions but do not make them feel awkward. Were there 20 contestants and 20 drinks? They might not remember the details without looking at their notes. Ask for general advice to improve your game which might include things that the judges saw but you did not necessarily do wrong.
Keep on trying. Many of the most winningest bartenders here in Boston went through a lot of losses before they worked out what would win. And then it seemed like they could not be defeated.