I’m no pro on this subject, but I’ve learned one generic rule: do not view your competition as the bad guy. Learn from their experience and from their mistakes. You can even be on very friendly terms with them and make some deals on how to split things.
Example: You open a cell phone business. The guy two blocks down is doing well, but you see that he mainly deals in bulk (big company/employee plans etc.) with individual sales in between. You have the option of having a meeting with him and being open as follows:
I do not know the first thing about cell phone businesses so I hope this point makes sense. Good luck