This may not apply as well to your specific market/service, but for any clients that may have an Instagram presence you definitely should be following, liking, and commenting positively on their posts/feed. Where else can you give a "handshake and business card" to an unlimited number of prospective customers before even crawling out of bed. Aside from the rich and famous, most small, or even larger, businesses and business owners pay close attention to any Facebook/Instagram activity, and it can really make it easier for them to choose which printer/sign shop to go with.
Make an Instagram "business" account and post a few photos of your recent projects, then just start liking and following every possible potential local client. You would be shocked how many people make a decision based on what they saw on there. You don't need to follow anyone except leads, that's the beauty of it I think people overlook when coming at it from a business perspective.
Great way to have a dead simple portfolio of projects available online, while potentially grabbing a captive audience at the same time.
No I don't work for Instagram...
I will also give a big thumbs-up to taking a few months or a year to run Google ads. It really is the new yellow pages, so any way you can scramble ahead of everyone else will only help in the long term. I don't use it all the time, but I do feel that it's important that a small business do it a few times, especially when initially trying to build initial visibility.
