To make an effective plan, there is a famous rule called 4P's. Here, P's stand for Price, Product, Promotion and Placement. In this another P is added called People. Today while doing digital marketing or the traditional marketing one should understand people or the customers you are dealing with. It's important to figure out what is significant for the business, and later make a plan accordingly.
Risk _ in our marketing plan we shouldn't only concern about making money or positive points, we also should address the risk we are taking. for example it is common for a marketing plan to capture things like, "require additional staff to handle sales call", "additional investment from the management budget will increase chances of increasing 10% sales target" and many more. Imagine if you can factor your risk earlier and think through it, wouldn't it be better for you?