This is a great question to ask when you are talking to someone with much more experience in your industry.  Generally, they will tell you to look out for this or that.  Get your accounting on track from day one, charge the proper amount for your services, build a savings for a rainy day.  Sometimes we want to do all things in the business, sales, install, accounting, etc.  And there is no way we can do all those things effectively long term.  Sometimes, we do not have a choice but to do all those things but when we can afford to give them up one by one, it frees you up to do the things that you love to do.