Photos: Courtesy of Homepolish. 
Photos: Courtesy of Homepolish. 1. Source your image
I love seascapes, so I purchased a vintage paint-by-numbers painting on Craigslist for $150 (check Etsy for cheaper options). Once you have your piece, take a photo of it. You can also just source an image online of an old paint-by-numbers that you like. I have a whole Pinterest board of them.
2. Build your canvas
I purchased stretcher bars and canvas. This is the least expensive way to build a giant canvas, but if you're feeling lazy (and wealthy), just buy a pre-stretched canvas. If you want to make your own, here’s a handy tutorial.
Photos: Courtesy of Homepolish. 3. Trace your image
Using an opaque projector, trace your image onto the canvas with a pencil or chalk. This part can be confusing at first, but you can always fix your mistakes with paint, so don’t be too precious with it.
4. Color in the lines
Using your original image as a guide, fill in the lines of your painting with corresponding paint colors (opt for paint with an eggshell or flat finish, which makes mistakes less apparent).
Photos: Courtesy of Homepolish. 5. Cover your mistakes
No surprise here, but painting gets messy. Make sure to keep some extra containers of all your colors so you can go back over your mistakes and make the whole thing look perfect.
6. Hang and ogle away!
Large-scale art is such a glamorous addition to any space. I think it looks especially exciting over a sofa or a bed.