Social Media is not as easy as some people make it seem. It is also not as hard as it appears, the trick to it all is - specially in getting others to truly like you - is to find a niche and speak only to that interest.
With that in mind you could narrow down hashtags to cater situations. For example, you used the word #art (Besides being a global strategist I am also an artist and my first love was painting) I can tell you that the hashtag art will generate a broad exposure, specially on Instagram but then you need to narrow it down to situation such as who's posting/who you want to target? The person? the building? the buyer? who? You can narrow down #art to #artist or #artists then to #artgallery then #abstract or #popart then tools used such as #stencil or #photoshop and then possibly add to your hashtags some muse tags that might provide inspiration for artist such as #scenery #galaxy #landscape #murals #wearableart etc

You can also type these narrowed tags one you have identified them and see the "related:" suggestions Instagram gives you.

My name is Humberto, I'm the founder of www.Unthink.me, a digital marketing agency that brings big business tools and experts to small growing companies with little budgets. Best of luck in your efforts!