If there is one rule for success, I believe it's "keep things simple."
I know that, ironically, this advice sounds, well, simple. But, don't underestimate how hard it is to follow.
Human nature is such that we have an urge to complicate things. We think it shows off our abilities, sophistication, and intelligence. We hide behind complexity to mask our insecurities. We think that if we only do the simple stuff, we are "naked" - there is nothing special to distinguish us and we are replaceable.
The truth is we are replaceable no matter what we do. Employees, businesses, suppliers, vendors, etc. - they can all get replaced by their competition. But, if you keep things simple, and succeed, and give a delightful experience to your customer (everyone has a customer), you have a better chance to stick around.
Simplicity, success, and customer delight go together because, when you keep things simple, they tend to be robust - less goes wrong, and there is less to maintain and less to breakdown. Simplicity leads to accuracy, reliability, and lots of "up time".