Do something, take a step forward.
If you're in sales and you have no idea how you're going to hit your sales target, just talk to someone new about what you're doing. Don't worry about your pitch or the numbers or anything - just have a conversation. And then another, and another.
If you're an artist and you're frustrated with your work or lack thereof, just make something and show someone. Don't worry if it's good or bad just make it and see where it takes you.
If you're a 20 something (or 30, 40, 50 etc) not sure of where to go in your career, just try something new. Work at something new and see if something's there. If it's a dead end - try again. Steve Jobs was absolutely right when he said, "You can't connect the dots looking forward; you can only connect them looking backwards"
If you're out of shape and feeling unhealthy - move your body, eat something that's good for you today - right now. Don't stress about a diet or finding a trainer, just focus on doing something right now that is good for you.
If you're constantly feeling strapped for cash and you don't know how to start saving money, set a dollar aside today. One, single dollar - $1.00. I don't care if you're making a good income, if you're constantly living pay check to pay check, you need to feel what it's like to have extra money set aside. It doesn't matter if you use a piggy bank, shoe box, savings account, checking account, or money market mutal fund, put a tiny amount aside on a regular basis. By starting small, it's painless and you'll build that muscle. Bottom line is - just start, right now.
What about if you have a personal website and you aren't happy with your ideas, and you think your writing sucks at the moment? Do what I'm doing right now and write something. Talk about something you care about and put it into the world. I figured I should probably follow my own advice.
Of course we all know that life is short and time is limited. We should also know that waiting for outside events or a bolt inspiration to magically change our situation is stupid. So here's my blog post. What are you going to do today to move yourself forward?