Capping on foam will also take care of the O2. I've gone from taking a racking cane jammed inside the cobra tap, to using a stopper on the racking cane and release pressure as it's filling. I now have a beer gun, but when I'm filling only a couple bottles, I use a bottle filler tube that fits into my perlick taps.
As mentioned above, cold bottles and low pressure. Try to fill from the bottom of the bottle instead of pouring down the side. Either cap on foam or hit with CO2 if you can.
Good luck with the competition ( and getting an entry)!