I have since stopped actively freelancing, but I did it from 2011 to 2017, and I still have just a few clients left.

Short:
Lived in another country for a while, made a website for a nonprofit there for free, built up some experience. Moved back home, jobless, applied to Craigslist programmer job, boss had a friend who needed some web work, and told me to charge for it, which helped me understand invoicing.

After that, I began to solicit Craigslist for clients. I definitely had some great luck there, just know most people want to meet you when you are local and they prefer it so they can know you are in the same timezone as them if they have issues.

My brother, working as a waiter, who makes conversation, always keeps me in mind, and has some of my business cards handy for when he wants to refer me. I've gotten two clients from him, and one of those clients lives in Africa! My girlfriend also deals well with office gossip and we've been able to acquire a client or two that way as well.

I acquired business cards which I hand out for networking and whoever comes into my house, contractor/plumber/electrician/etc. I always let them know what I do and get their business cards (many of them do side work for extra money) in case they need something or they wish for me to refer some personal business to them.

Currently trying to start a drone business and working with my real estate agent (the one who got me the house I live in), whose giving me some practice and helping me to touch up my videos. Free work for now.. but having houses I can fly and film in and around to practice with without any questions is a nice balance at this time.

Anyways.... most of my work obtained has been through Craigslist, referrals, or repeat work, and sometimes even networking. One thing that I've always been: the web dev who picks up the pieces when the web dev before me disappears without a trace or just isn't doing the job of maintaining or fixing the website. I also answer my phone within 2-3 hours when any of my clients call. Clients have peace of mind when you answer your phone and affirm to them that you are now aware of the issue and looking into it. These types of clients become very loyal to you because if they are running a business.. and something happens to their website, the only person that matters at that time.. is you.

I've been lucky thus far... but I am beginning to wind down in the freelancing field so I can focus on other things.

My advice to you is to get a few websites/clients under your belt and you should probably go through Craigslist. You can ask a few of your friends if they want websites if you are just trying to build a portfolio and either build free or charge a small fee. Get some business cards while you are at it too. If you have a few under your belt already, go around your neighborhood and jot down in your notes all of the local shops in the area... go visit their websites, and note which ones need work. Then return to those businesses and ask if they are looking for a new website and let them know your prices. Hopefully you can also entice any clients with a referral bonus to them... if you charge $1500 for a website, than 10% isn't a bad deal for potential future referrals and motivation from your current clients.