Book marketing just to sell books isn't a very useful goal and doesn't help you with strategy. Think instead about where you want greater visibility, who you'd like to build relationships with (readers or gatekeepers—or even specific brands?), and how you want to position yourself for whatever is next in your career. Plus, it's tough to earn a living from book sales alone, so you need to be thinking of other benefits that might arise from your marketing.
While self-pub and traditional pub books start out differently in terms of marketing (especially pre-publication), the longer a book is around, the more the marketing looks the same. In the long game, marketing becomes more and more driven by reaching new readers, advertising to new readers, etc.
Knowing your reader and comparable authors or titles will help immensely when developing a marketing plan. To get started: