How do you get clients?

I've been doing SEO work for a guy who has clients himself and he outsources work to me he keeps me going with about 10 hours work a week but I'm now looking into attempting to get work of my own. How does one even go about finding people who require SEO done. I've tried Freelancer for the last 6 months and have gotten nothing from it and I have also in the last month began emailing various businesses locally about their SEO. Any advice would be much appreciated. (I Live in Ireland btw and generally website SEO is shocking here on websites)