Here are some standard (and current) best practices for your video, which you'll want to make sure you comply with so your videos don't run into any technical problems while being uploaded or streamed. 

Pixel aspect ratio must be 1:1 (square). Other aspect ratios are a thing of the past! 

Use standard aspect ratios. We take almost any video aspect ratio; however, using a standard aspect ratio will guarantee that your video looks exactly how you want it to after it's been processed. 

Some standard aspect ratios are:

16:9
9:16
4:3
1:1

Use standard frames per second. It's recommended to use standard fps. The most popular are: 25fps, 30fps and 60fps. Keep in mind that the more fps, the higher quality your video will be, but also the heaviest, so keep in mind the type of video, audience and use you'll give to it before you choose one.