What are best practices or effective strategies on expanding a recruiting search geographically?

eg. I have exhausted (or close to it) much of the local market for a particular position.  I want to expand the radius of my search to 100 miles, 200 miles, 500 miles, etc., hoping that someone will be open to relocation.  What is the best way to go about this both strategically and tactically?

For context, I am an in-house recruiter for a financial technology company in Central NJ. The position I am working on would be equivalent to a Lead Software Developer for a new product.

Thanks in advance!