Trina, that lesson is one which seems more difficult to learn when you are just starting a business as compared to later when your business is established.
When I first started I had zero revenues. My word of mouth hadn't begun. I offered many varied services to generate cash. There is a time when cash generation is the main priority - however, even with that I never would work with customers that I didn't respect, or people I didn't want to be around. I had done that in corporate.
Over time, now in the seventh year of my business, learning to focus on my strengths is something I adapted in the last couple of years.
It is a treat and a reward for a business owner to find others who love to do those projects and aspects of your business that you don't like, and that take you longer - and most importantly - away from your core business focus.