Anyway, over the years, I've made lots of mistakes at Leadville, so accept what follows as wisdom gleaned from many foul ups! Also, check out the entire Leadville section I have on this blog. There, you can read detailed descriptions of the first half and second half.
1) Stay hydrated. The race is between 9,200-12,600 feet. That high up, you lose a ton of water. The problem is that you don't realize it because your sweat evaporates super fast in that dry heat. So go into the race well-hydrated and stay well-hydrated throughout.
2) Whatever you do, get out of Winfield. Winfield is the halfway point of the race, right smack-dab in the middle of the Hope Pass double-crossing. When you get to Winfield, you might be thinking, "Holy hell, I have to cross that damned mountain again! How am I gonna do it?" You might even want to drop. Don't. Get out of Winfield and just dig deep as you go up the backside of Hope. It'll get better.
3) Never, ever drop at Twin Lakes inbound (mile 60). When you come into Twin Lakes, you might be reeling from the Hope Pass section. Sit down and regroup if you need some time. Whatever you do, don't drop! Based on the numbers alone, the odds are great that if you get out of Twin Lakes you will finish the race.
4) Have plenty of warm clothing for the nighttime hours. By warm clothing, I'm not talking about a long-sleeve tech tee. I'm talking about insulated tights, an insulated jacket, thick gloves/mittens, and an insulated hat. The temperature at Leadville can get into the 30s---even 20s--at night. The last 13 miles, which take you along the lake and into town, are especially cold. Be prepared. If you leave Mayqueen with little on and it's still dark outside, you'll soon find yourself in deep trouble.
5) Soak it all in and have fun. It's easy to get so focused that you miss the scenery and don't have fun. Here are a few spots where you should make a point to look around you and smile: Going up Sugarloaf pass on the outbound trip (the sunrise is spectacular); right after the Outward Bound aid station, look to the west and you'll see Colorado's two highest peaks--Mount Elbert and Mount Massive; and the top of Hope Pass (both ways), which is in my opinion one of the prettiest views in Colorado (see video below).
Bonus: No matter how bad it gets, remember these words: "You are better than you think you are and you can do more than you think you can." The key to Leadville is living those words and "digging deep."
There's a lot more but those are the key tips I wanted to share. Chime in if you have some other tips of your own!