When it comes to buying frames, there are a few points you need to consider to make sure you are able to find one to fit your needs. It's also important to know the kinds of frames that are out there. The first thing you need to consider is how you are going to display your frame. Is it going to be hung, propped up on a shelf, or use the back easel to display on a table?
If it's going to be on an easel, the first thing you'll want to check is if it has an easel - duh. You'll also want to check if it comes equipped with hanging hardware. That may be something you don't think to check for. - If it doesn't have it, you can easily install a bracket and be good to go!
The next thing to take into consideration is how often your pictures are being changed out. The most common ways a picture is secured in the frame is by bendy bracket or twist bracket. You can see below what the heck I'm talking about.
If you are going to be switching out a picture yearly, do not get a frame with bendy brackets. Over time they will snap off and break. You want something that will wear well like the twisty ones.
Let's talk glass vs plexiglass. Better quality frames have actual glass as opposed to cheap frames that have plastic or plexiglass. For longevity reasons, glass is the way to go. The only exception would be when getting a large print (I'm talking 24x36) that you intend to hang, plexiglass might be the safer choice. Especially if you have kids running around. I say use the plexiglass for the younger years and as the kids grow up, replace the frame to a nice glass one. Ikea has tons of glass and plexiglass options, that are both affordable. You just have to be mindful when shopping.