There are some good tips in the OP but I think he uses more bubble wrap and definitely more tape than is necessary. If you are shipping to a comp, try to consider that somebody is unpacking like 50 boxes. My amendments would be:
1. Get the perforated bubble wrap and use one sheet per bottle. Attach it with a rubber band (works as well as tape, much easier to unpack). The point here is just to make sure glass never touches glass.
2. One layer of the large bubble bubble wrap around the outside wouldn't hurt anything.
3. Pack the box TIGHT. Preventing movement is 29% of the battle (60% was preventing glass on glass contact).
4. I very recently heard Gordon Strong on The Brewing Network talk about building an insulated box. I did this for NHC first round this year and it isn't all that expensive and was very easy. Just get the pink foam board and cut pieces to line the bottom, sides and top of the box (just score it with a knife and it breaks pretty clean over your knee). Then you pack the box and leave it in the fridge over night. If you don't have that much cold space, just get the bottles really cold and then pack and seal it. This apparently got Gordon's 2 day morning delivery shipped beers to Oakland in June still COLD. My wife just went to visit family back West and we sent some commercial beers this way so she could unpack them and get a first hand idea of how well it works. We also plan to do some experiments where we leave an uninsulated, insulated, and insulated with a cold pack box out for a couple days and see which works best. Unless I can't figure out how to make it work at all, I will use this in warm weather months from now on for competitions or just sharing.
ETA: I used 1" foam board, not sure what GS used. It does happen to work out perfectly for standard 12 oz longnecks in a 12" box though.