Running an even pace is definitely the way to go. But running negative splits often works even better.
You can make this happen by going out slightly slower than race pace for the first, say, 20 to 50 percent of the race.
5K pacing: If you're figuring to run a 5K at eight-minute-mile pace, try to go through the first mile in around 8:10 (i.e., slightly slower than race pace). For mile two, aim squarely at eight minutes per mile. For the last mile-plus (especially the last half-mile), go hard.
Marathon pacing: Let's say you're planning on 10-minute miles for the race. For the first three to five miles, go a little slower than this maybe 15 seconds per mile slower. This will give you plenty of time to get into the groove of this long race.
Between miles five and 20, cruise at your goal pace of 10-minute miles. For the last six miles, pick up the pace and finish strong.
Adjust your pace accordingly on hilly courses and windy days: The key is to maintain the same level of effort throughout the race. If you do this, you'll naturally be going slower than goal pace on the uphills (or into the wind) and faster than goal pace on the downhills (with the wind).
To gauge effort on the uphills, use your breathing as a guide. If you're huffing and puffing, slow down until your breathing normalizes.