The marketing plan that has a feedback cycle, from 8th stage back to the 4th. That is because sometimes during the planning process, we might need to perform stages 4 to 8 several times before the final plan can be written.
You must know your competition in and out. Keep your friends close, but keep your competitors closer. You need to know all the things that you learned about your customers except fill in the blank for each competitor on all of those above items. Learn how you are the same/ different. Learn the similarities/differences about each product and service you offer. Learn how they sell or promote their products /services.