Redbubble is a print-on-demand site offering a wide range of products. I love Redbubble's T-shirt and apparel options. Prints, bags, pillows, and many more accessories and home decor items are available.
Etsy is my shop for original paintings, signed prints, cards, postcards, stickers, and other limited-run items. I personally package and ship these out from my home studio in Sioux Falls, South Dakota.
A huge variety of products are available at this print-on-demand site, including phone cases, shirts, zipper bags, clocks, pillows, and more. I especially like the prints and framed prints here.