lots of good advice here - one gem I would add that it took me many years to learn and appreciate. If you want to make money, do business with people who have money. It sounds obviously, but this little elegantly simple principle was an essential step in turning our business into profitability. One companion addon I'd offer that contextualize the first lesson, was be ready to invest in your clients. Again, obvious but over the years its been the clients we've put the extra effort and attention to who have succeeded (not just with us, but in general) and because of that these folks end up being lifelong partners and supporters of what it is we do/offer.