Some people have twenty years of experience. Some people have one year of experience twenty times. The difference? The former keep track of their progress and learn from their mistakes as well as their successes. The latter keep trying something new, and have to re-learn the process every time.
Make it easy on yourself -- mark your trail. Make a point of writing down everything that works and everything that doesn't as you work through your marketing plan. That will help you focus on the good ideas and eliminate the bad ones the next time you're doing marketing for a book. Give yourself some evaluations. Figure out if you could do something better next time, or tweak an unsuccessful effort in order to make it successful.
If you keep track of everything you do in your marketing plan, you'll discover it moves along much more quickly the next time you need to do it. So make lists of your activities. Keep track of names and emails and phone numbers. Grab contact information to the producers and hosts and editors you're in contact with. Make notes of the ideas you found helped you sell books. Send thank you's to the people who really assisted you along the way. If you don't keep track of your work, the next time you have a book releasing you'll have to do all this stuff over again.
If possible, talk through the plan with your team -- perhaps someone from your publishing house, as well as someone who helped you get the work done. Get their input into the ideas that worked best. By focusing on the best practices, you'll find yourself improving at the marketing side of the business, therefore allowing yourself more time to WRITE in the future.
That's it -- my ten steps to creating a marketing plan. I hope you've found it helpful.