Costco is by far the cheapest and best value. More on reddit.com

Costco. More on reddit.com

If you are shooting standard 3:2 aspect ratio, you will need to crop of the sides, so keep that in mind when framing your shot, especially if it’s a group of people. Just give a little breathing room. Not familiar with the R7, but if there is a choice for 4:3 aspect ratio, that will get you the closest. There will still be a crop to get to 4:5 (8x10) but it will be minimal and you won’t have to be as paranoid when shooting. You can crop either in your processing software or in a lot of cases even when you upload to the print service. My own preference is to crop the image to the correct aspect ratio before uploading. Takes a little more work if you are doing multiple sizes, such as 8x10 and 5x7, but at least you have total control. My advise is upload a couple of test photos to your selected print service and see how they handle things. You can always delete the images. Note that uploads will require jpegs. Whether you shoot raw or jpeg is your own preference. I’m usually a raw shooter, but on a couple of my cams, I actually prefer the way the jpegs come out. More on reddit.com

Frames are usually sold according to the size of photo or print that will fit into the frame. So, for example, an 8x10 frame should fit a photo that is 8x10 size. Some frames come with matting, which is an extra layer of material, sort of a frame inside the frame, usually in a neutral color such as white or gray. The matting is optional, but if you want matting, you can check the size of the frame and the size of the opening in the matting to confirm that the photo will fit. More on reddit.com