Here are some or my thoughts, strictly by way of illustration. You can probably think of better ideas.
- Liking: Know the potential employer well enough that you can show how you would fit their needs, including their cultural profile, if possible. Demonstrate your sensitivity to their needs.
- Social proof: You can offer suggestions in your marketing documents that the techniques and approaches that you use are becoming trends, or that more and more people with your qualifications are being hired.
- Consistency: When you network with a potential employer try to get some commitment to a reasonable follow-up from that individual (without being overbearing or obnoxious about it).
- Scarcity: At the very least avoid giving the impression that you are desperate for employment. Try to suggest that a number of employers are or would be interested.
- Authority: When you mention a college diploma or other qualification in your marketing documents your are implying that experts have endorsed your level of education.
- Reciprocity: At the very least, send a thank-you note.
You can combine some of these points too, clearly.