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.
You need to itemize your budget with breakdowns for advertising and promotions. Include any design, development for needed materials to facilitate the marketing. List the media outlets that will be used to execute your marketing plan and break out the online, social, e_mail marketing, e_brochures/e_catalogs, TV, print, radio, PR, tradeshows, sponsorships, philanthropic partnerships, direct_mail, telemarketing, and other outlets. I would also identify which components that will be completed in house and whether you will have an outside agency to help with your media buying and planning.