While looking for some materials on my site, I found a couple of things that others had written about getting starting in the business of statistical consulting.
AnnMaria De Mars. Since you asked me … four tips on getting started in the statistical consulting business. AnnMaria’s blog, 2012-04-06. Available in html format
Melissa Kovacs. Statistical Consulting Clients: How to Get Them and How to Keep Them. AmstatNews, 2019-09-01. Available in html format