My best suggestion right now is to spend some time reading through the existing threads here in the Marketing and Networking section - there are tons of great resources and conversations related to both of these questions.
I think you'll find that different methods have different results for each VA depending on the target market and services/specialties being marketed. There isn't a 'one size fits all' marketing plan.
Take your time reading through the info here - experiment with the various approaches to marketing, and be sure to post back with your own results!