1. Practice finishing fast and strong. Do some of your runs in a negative split, which means your second half is faster than your first half. Practicing a progressively faster pace will train you to finish strong during a race.
2. Improve your physical and mental toughness. Including some speed work in your training will improve your strength and confidence, and help you feel tougher at the end. Doing a few miles of your long runs at race pace is another way to build your confidence and strength.
Also see: 8 Rules for Speed Training
3. Do some hill running. Doing hill repeats will make you stronger, as well as improve your running efficiency and increase your lactate threshold. All of that means you'll feel a lot more confident and strong in the home stretch.
Also see: How to Run Hills
4. Increase your strength and power. In the final stretch, your muscles are fatigued, but they still need to work hard. Incorporate strength training, like lunges and squats, and plyometric drills, such as high knees or skipping, into your training to build strength and explosive power.
5. Find your next gear. Do you do all your training runs and races at a consistent pace? Lots of runners do. And while consistency can be good, there's comes a point all races when you don't have to hold back anymore. If you've done some training to run faster (see above tips), then the last step is to mentally make that switch and tell yourself, "It's go time."
6. Don't start out your races too fast. One of the biggest reasons runners can't turn it up a notch during the final stretch is because they went out way too fast. It's easy to start at too fast of a pace because you're feeling strong at the start of the race. But don't assume you're "putting time in the bank" by shooting out of the gate quickly -- you'll pay for it at the end. Be conservative in the beginning and you'll still have something left in the tank for your finish.
7. Talk to yourself. Who cares if the person running next to you thinks you're weird? Repeat a mantra to yourself that helps push you through to the finish. Sometimes giving yourself a little pep talk and saying things such, "I can do this!" or "I'm staying strong" can help you through some discomfort on your way to that finish line. (And if you tend to get embarrassed, you don't have to say it out loud.)
8. Focus on picking off other runners. You may feel like you're running out of steam, but your mental focus can really help you stay strong and steady. Start "fishing" for other runners in front of you. Imagine yourself hooking a runner in front of you with a fishing rod and start reeling them in. Once you pass them, find another one to catch and pick him or her off. And don't forget to smile for your finishing photo.
Also see: Common Racing Mistakes
Finish Line Tips
Running Etiquette Tips for Races
4 Drills to Help You Run Faster