I’ve seen some form of this question a ton, pasted all over the Q-and-A websites. Here’s a couple of ideas to get you started.
Disclaimer: this is pretty much “Internet Marketing 101,” so if you’re here for marketing goodness, this isn’t it. This is specifically targeted toward individuals not sales-and-marketing minded who need to start somewhere.
If you can afford it, start with a lead funnel. If you’re a web developer, you can design it yourself.
Set up a lead funnel, with a splash page capturing contact info (at a minimum, first, last, company, email, and phone). When prospects opt-in, follow up with emails and SMS messages. Use an existing ESP service that also provides SMS messaging. If you’re not good at copy, hire someone who is.
Advertise to your target audience with Facebook and Google (chances are you’re gonna need to get really creative here). As you get clients, ask them for referrals.
Pounding the Pavement
If you don’t have the money to advertise, it’s time to start pounding the pavement. You’re going to have to start selling your skills. There will be lots of refusals. Ask anyway, and ask for referrals (“Do you know anyone who needs a website, it needs their website modernized?”).
If you’re really cutthroat, go find websites that aren’t ADA Compliant (in the US), are insecure, or are in dire need of SEO help (depending on your specialty). Run a preliminary scan and provide that free-of-charge with an introductory email.
Every time you finish up with one client, ask for a referral. Every time you’re told “Not interested,” ask for a referral.
Keep copious notes on the businesses you contact, and find out what their other needs are. You’re talking to a lot of people, and even if there’s not a fit for you right now, you might be able to bring others together. These are the actions that benefit you in the long run.
Never be afraid to ask for the sale.