In our area, some very good artists show at the local street fairs. No theme to our collection, although that makes hanging prints occasionally challenging!

Local art galleries. Art shows and local fairs can be a source as well if you are on a budget! You might even find something you like at local high school and/or college art shows. I have seen some very good work in schools.

Saatchi has a great online gallery now. Tremendous selection - very inspiring.

I like looking at Minted for posters and graphic art.

I've been on an art buying spree lately, for my new home. The general advice here is don't buy art to fit decor, but buy what you love over time, art will find you. I have to admit, I'm not nearly patient enough for that advice. I've actively sought out pieces I love AND match my decor. I've used Etsy and Artfinder. I've been amazed at how affordable really amazing original art can be,

As far as guidelines, I can only tell you what I have done, i'm not sure if it is "right", but it has worked for me. some examples below of the process I've gone though for different pieces.

I wanted food themed art arranged gallery style in my kitchen nook. I searched on Etsy and found an artist that I really like the style of her work. She didn't have all the pieces I needed available, so I asked if she could create a coordinating piece. She actually created 4 and let me choose!

So in other places I didn't need custom pieces. I found an artist I liked on Artfinder, but wasn't sure which of her painting would look good hung side by side. So I contacted her with a number of pieces of hers I liked, and asked her to recommend two pieces she thought would work together. Here they are

And them sometimes an artist has pieces for sale that already coordinate, like these. Top photo pieces are from Etsy, bottom photo, pieces are from Artfinder

All the above, and...

You might want to "Like" or join a few art sites on FB. All new original postings will go through your feed daily. Many artists also have prints if you contact them. Also, some prices are negotiable. On the most popular sites there is art from around the world but remember about the shipping costs. You might even find some artists in your area so you can personally view.

Don't limit your FB art page groups to join to the exact type of art you prefer. For example: I'm not personally big on Sci Fi art but was amazed at the few modern abstracts-ish I found tossed it.

The other cool thing about saving some pages of artists you like is if you travel. I know if I go to Cuba there is tile collage artist I will look up. There is an artist I love in Italy and several others in Europe. I haven't made the effort yet but certainly will in future travels.

I've picked up things locally over the years from a variety of sources. I have a couple of artist friends and have some of their work. Some of the local cities do annual "open studio" events. There is an art studio for disabled adults near my work that has an annual open house where I have picked up a bunch of inexpensive pieces. I've picked up some items at craft fairs. I have one painting on my wall that was done by a 9-year-old at an art-themed birthday party (but I really like it). I have a painting my brother did in high school art class. And I have a few prints from places like World Market. Lots of local cafes and other businesses have a gallery showing rotating local artists (I don't know if I have every bought anything that way, but I definitely keep an eye out).

Here is a pic I like. If I make a grouping using this or something similar, would I need to look for other water related art for the other pics?

That is beautiful, I can understand why you'd like to build a collection upon that piece. Doe the artist have other work you like? If not, maybe look for pieces with the ocean theme, but not the same beach, waves and sky. Maybe seabirds or sail boats, of sea cliffs, as ideas? I'd probably want one color to be in all the pieces you group together, either the color of the sand, the water or the sky.

Online: Etsy, Chairish (never made a purchase yet, but many great works), EBay, Everything But The House..1stDibs is my dream source but highly unattainable:)

Real life: art galleries, local art and craft festivals, pottery shops, flea markets, vintage shops, travels. When I'm in my home country I usually go to certain artists' colony I love..it became our tradition. so I can even collect-albeit very very slowly, takes years upon years-works of somebody whose art speaks to me the most. I also have my favorite pottery shop in other city-I always go there to see their work, it's amazing. Sometimes I buy something, but even if not-it's a pure joy just to look at.

Here, we have artists' colony too..so we visit there, and come to see the festivals. I also follow the certain artist I love. I'm subscribed to her newsletter. I have only one painting from her by now, but it's one of my favorites.

Travel can be highly rewarding in finding new art. It's reward by itself of course-to be exposed to different scenery, culture, colors, feel. But since I love art-I actively seek it out. I might have zero money for it, but I will always find galleries, festivals, vintage shops..Just to look around and be inspired. And sometimes you can be lucky in getting amazing art for cheap. We bought a wonderful artwork in Nicaragua, by an acclaimed artist, very talented one..frankly, here it would cost at least twice as much. if not triple. I consider myself very lucky, finding this great art and being able to afford it. I love it.

And another small category-things that were gifts from friends and family. Sometimes it's something they or their kids made themselves; sometimes, a ceramic piece they know I'll love.

I have all kinds of art in my house, from kids' works to true masters' paintings or drawings or etchings..it makes me exceptionally happy because each piece reminds me of people I love, places I've been to, times, good or vulnerable, I found myself in..

PS I have no guidelines but I find myself naturally drawn to certain subjects. In my case it's very simple: flowers, animals, places, and people..)))

With people, I noticed most of the portraits I'd be drawn to, are either of young girls, or old men..)) Not sure what it says about me..

At one time my area had quite a few flea markets, some upscale, and I found some good paintings there. My other source has been e-bay; I've never looked at etsy but will now. I would advise buying genuine art rather than reproductions; they impart a completely different atmosphere to your home.

As for how to hang art in groups, I don't believe they all have to be the same. I try out groupings on the floor first and usually achieve the result I want.

The last picture is a different version of the one above it - I get bored

PS the more piece is special to me, the less I'm inclined to include it in a grouping..Maybe that's a pity since I do love groupings. But I also want some art to be..how I would put it..by itself. I want to concentrate on it solely, rather than being a part of a grouping.

You don't need to go always by the subject; you can use color as unifying factor, or technique, or certain mood..

I do hope I'd be able to do at least some groupings when in new house, even simply because it's much smaller..)) Less space, Gallery walls or groupings would make sense. But I think it won't be an easy task..

Seems simple, since I have enough art for several little "galleries". it's seemingly very obvious what should go with what. But it won't be.

I'd explore more what you are drawn to..so it won't be "I have to buy this or that" but "I love it". After several "I love it", you'll see the common thread..it might not be visible right away, but it will be there, waiting for you to discover it.

Meanwhile, I'd just enjoy one beautiful picture. The others will follow; maybe not right away, but they will. it's not something you suddenly stop loving when you're done with decor. The art, I mean. It takes you deeper and deeper and deeper..like in that song:)

I seldom find art that I like around my own town even though there are plenty of galleries. But when I go on a vacation, I find a lot of beautiful art. May I recommend to you the "vacation method" of art searching? ;)

Abby, that Saatchi site is gorgeous. I'm hooked.

I have to echo what Ingrid said:

I would advise buying genuine art rather than reproductions; they impart a completely different atmosphere to your home.

Art is totally personal, so really, buy what you like, everything I'm writing here is truly IMO. But look at some original art, Etsy, Artfinder, Saatchi. I have been amazed at how affordable amazing original art can be. Framing that really enhances artwork is quite expensive, so make sure before you invest $300 in framing that you truly love and appreciate the artwork. For me personally, original art has a certain magic, that even the most beautiful print can never capture.

My go-to places are thrift stores and the junky kind of antique stores.

They are also a place to find cheap frames - toss the art that's in them.

I have bought from eBay, but it's a crap shoot on condition.

One other source to suggest: http://fineartamerica.com/ - I came across this after a recent beach trip. I was browsing at some galleries but couldn't make decisions in the short time I had without kids in tow. I googled a few of the artists whose work I liked and found them on this site, and since then I've been trolling for similar stuff. I like the idea of Etsy but I've had trouble figuring out how to search the site effectively for original art.

I spent a few hours on Etsy and found some on there I like. I do like the idea of more original. I also checked out the Fine Art site and that has a bunch of options too. What about Red Bubble? Now to try and figure out if I can figure out something with the size and subject options.

I agree with lazy-gardens. Also look for estate sales and consignment shops. Lots of lovely pieces, and most are already framed.