A few years ago, I came up with my 10 commandments for consulting. To be honest they probably make sense for life as well, but we'll stick with consulting here.
I'd be interested to know if you have any others that should be added.
I. Always listen to the client. You may need to help them think differently, but you can't understand them if you don't listen.
II. Always consider the impact of what you are doing on others.
III. Never assume that you know better than anyone else. You may have more experience in different areas, or more qualifications, but that doesn't mean you are better or know better. Remember that.
IV. Always be ready to learn something else. There isn't a week go by where I don't stop for a second and realise that I have discovered something new, or experienced a better / different way of approaching something.
V. Share. Share your knowledge and experience with others. This may be through mentoring people or just sharing on forums like Back2ITSM
VI. Start the day with a good cup of tea or coffee. Does wonders for your approach to life.
VII. Be nice to others. Independent consulting is generally about word of mouth, whether that is recommendations or advice to stay away, so always treat people well and be professional.
VIII. Don't believe EVERYTHING that you read. If you are going onto a client site to look for improvements for example, then you will need to find out the core information yourself. You can't just take people's word for current state; it may be tainted.
IX. Don't overcharge your clients. This comes back, partially, to commandment VII. Clients are not cash cows. Yes they may think you are expensive, but they are getting your experience, knowledge and network, to enable work to be undertaken (hopefully) better and quicker than if they were trying to do it themselves. That doesn't mean that you can add hours on here & there to bolster your bank balance.
X. Always make time for personal development (& holidays). It can be very easy to get into the "must make money" mindset, but often you will be working harder and longer than full time staff, and so you must make time for a break. You must also ensure that you have time scheduled into your year for learning. This may be learning new skills, or new areas of interest, or just improving the way that you think or operate.