Make YouTube videos? Facebook? Here’s what we post in our YouTube descriptions:
“Support us (and get INSANELY good music from street performers) here: http://patreon.com/busk”
What do you write? Where else do you put things like this? Where do you promote your Patreon page? Let’s all share our little tricks 
I usually promote my Patreon page as an add-on to posts elsewhere. For example:
I recently posted a rough sketch of a new painting, and added on that patrons would be able to watch the progress as I worked, with a link to Patreon.
I posted again at the halfway point, with the same link, saying patrons were getting several progress photos a day, with commentary, and were able to ask questions and receive long, thoughtful answers.
When the painting was finished, I posted a direct link to the speed-through video on Patreon, showing it being painted start to finish. I mentioned that patrons had access to a dozen progress photos.
Something I was doing must have clicked, because after months of no new patrons, two new people joined up while I was working on my latest painting.
I use Buffer to post to Facebook, Twitter, G+ and Instagram, so I can write up the basic text and upload one photo, and then tweak and add hashtags for each service. Since IG doesn’t allow links in posts, I have a Patreon link in my profile.
I also host art exchanges, and at the bottom of each email I send to the participants, I mention that patron pledges help offset the time it takes me to organize collaborative projects, so if they’d like to see more of them, consider joining the tribe.
I try to be creative, and give people excuses to “join us”, telling them what they’re missing out on, rather than just asking them to become a patron.
I set up Recurpost to post to my FB page and Twitter every day. I made different libraries so it is a variety of content depending on the day of the week: museum studies on Monday, merchandise on Tuesday, WIP Wednesday, Throwback Thursday, fan art Friday, my most current finished artworks on Saturday, and I spotlight artists who have done artwork for me on Sunday. All are Patreon posts that cycle through Recurpost so whenever I make a new Patreon post, I put it in the appropriate library and it gets added into the mix. If they follow the link to my Patreon from FB or Twitter, they will see all of the other more recent posts that patrons (and followers as I don’t have anything behind a paywall) get instant access to. I try to word it so that they will be enticed to follow the link. For example if it’s a work in progress I invite them to come see where I am in the process or what I’m working on today or let them know patrons get to vote on what I work on next, etc.
I ask people to contribute and support my work now regularly via a monthly email to my subscriber base and a monthly FB Live video to my FB Group. I plan to add more links within my website to help people understand what Patreon is and how it serves my work.
I used to feel very E-beg-y about posting my Patreon links, but these days I’ve realized to succeed you just gotta be proud of your works and find a way to fit it in with everything you do.
Youtube • It’s the first thing in the description, and soon I’ll be having an end-graphic with the names of supporters and a big link to it.
Twitch • It’s in the description, my chatbot occasionally does a shoutout to ask donators to consider it, and I mention it at the end of every stream.
Twitter • It’s my pinned tweet, and occasionally I swap it out with my website in the links section.
Instagram • Sometimes it’s in my link section, and I often post ‘support me on Patreon’ in the description whilst hashtagging Patreon too. It’s a weird one, because Instagram really doesn’t like links.
I also post it around in Discords and places I’m at, mentioning it occasionally when on the topic of jobs. My largest supporter came from my Warcraft guild, which I did not expect.