What is everyone's favorite way to market their business?

I have a number of repeat clients, a separate facebook profile, and a separate instagram profile that I market on daily. I also post on my personal social media's to get more attention focused towards those pages. Sometime's I still notice that I have slower weeks than others, and I am wondering if there are any additional marketing ideas that I haven't tried yet!

I would also like to know where other people have had success so that I might be able to push things in the right direction!