1. Let's define successful. Each of us has individual goals and only some of them are monetary. But I take it you are asking about how to make money consulting! I'd be very careful listening to the advice of a consultant who isn't successful by that measure. I pledged to never accept money from someone who makes more than I do. Why in the world would they need me to get to the next level when I haven't demonstrated both good ideas and the discipline to do it? I'm grateful to have been consulting for nearly 20 years, and here are some specifics (fees billed, by myself). I hit my stride four years in and billed $307,000. For the next four years, it rose every year until I hit $686,000. Then decreased the next four years during the recession, reaching $339,000. Then back up in 2007 to $804,000. Then a tad down each year during three spinal surgeries and recoveries. Then back up to a new high in 2011 of just over $1 million. Now I'm at a sane level. :)

2. Recognize the "blah blah me too lemming-like" marketing speak you'll read everywhere and plant a flag on ONE specific mountain instead. Make it your business to be the unquestionable SME (subject matter expert) to defend it. Ignore the really bad advice to put your eggs in one basket or to just follow your heart and the money will come. (There are a lot of people following their heart and struggling.)

3. Consider these very distinct stages in how you make money in consulting, in order:
a. Forget spreadsheets; see your hourly rate as a positioning tool.
b. Get a second shift job to keep from compromising while you build it.
c. Fill >60% of ALL the time you work w/ recoverable fees.
d. Maintain >60% with an increasingly higher hourly rate.
e. Move exclusively to package pricing w/o reference to hours.
f. Build scalable income (webinars, books, etc.).

4. Be friendly but not too accessible. Experts are not accessible in developed cultures.

5. Take two stances, concurrently. Be very helpful in giving away terrific advice for free as long as you don't personalize it. Then charge ridiculous amounts of money to do so.

6. Figure out why you're in business. I'd suggest these three things, in this order:
a. Make money.
b. Make a difference.
c. Enjoy the process.
If you don't charge enough, no one listens and you don't have an opportunity to make a difference. But just charging a lot of money is very emptying.

7. Take chances and be different. On my website I tell visitors who aren't a good fit, list all my prices, and list all my competitors. I'm not sure there's a business in the world that does that!

Best wishes to you.