I like this post from Zen Habits called, Simple Living Simplified: 10 Things You Can Do Today to Simplify Your Life. I really like this one:
2. Drop 1 commitment. Think about all the things in your life that you’re committed to doing, and try to find one that you dread doing. Something that takes up time but doesn’t give you much value. Perhaps you’re on a team, or coaching something, or on a board or committee, or whatever. Something that you do each day or week or month that you don’t really want to do. Now take action today to drop that commitment. Call someone, send an email, telling the appropriate person or people that you just don’t have the time. You will feel relief. I’d recommend dropping all commitments that don’t contribute to your short list (from Item #1), but for today, just drop 1 commitment.
Simplifying is critical. That said, I think the more accurate word is to streamline, or reduce the clutter or volume. Because we are human and because the most rewarding experiences likely involved other humans, life will not be and ought not be simple - human systems are chaotic by nature and therefore complex.
That said, if our relationships are gunked up with crud and baggage, they can be more complex than optimal. So you should simplify there.
But the techniques in the Zen Habits post are more about streamlining and reducing, which is very important and beneficial. The more focused your life the better able your are able to deal with and relish in life's inherent complexities.