You need to know everything obtainable about your customers. This list will get you started. You will need their age, sex, marital status, income levels, education levels, geographic locations, where they shop, if they go to church, if they have kids, ages of children, political affiliation, what they like about your company, what they don't like, why they shop with you, what they value about your products/services, what they like the most/least about products/services, and whether prospects are unaware of your brand or products/services. Customers want you to know certain things about them and if you do, they will remain loyal to you as you take time to know them.
Planning and Monitoring the Budget: A marketing budget planned to the smallest of details is very essential in a marketing plan. You have to be realistic and exact, and base the budget on your goals. You will also have to monitor the budget, track the expenses and analyze the spending on a budgeted and actual' basis.