Every business is different, so it's hard to give you an exact answer that works for you but generally, when clients come to my agency (https://www.brotskydesigns.com) we follow these five main points:
1. Collect - We start by research demographics, collect data, etc.
2. Plan and Organize - We come up with a marketing strategy with hit lists, schedules, and budgets.
3. Deployment - We will start our plan and let it take effect.
4. Analyze - We review marketing data and figure out what worked and what didn't work.
5. Repeat - We fix our mistakes and continue doing things that worked.
I hope this helped. :)