To work with Overlay Footage in your desired editing software, simply drag the overlay footage over your desired footage in the video editing app of your choice and set the blending mode to Screen, Overlay, Color Dodge, Add, etc. Add some color correction/grading, adjust the levels or alpha for intensity, apply blur and hue effects to get different results.
With your footage selected in the timeline, navigate to your effect controls and select the dropdown arrow next to Opacity. Hit the dropdown menu next to 'Blend Mode' and select your desired blending more (Usually Overlay or Screen).
In this short tutorial below, CasualSavage shows you how to use overlays in Adobe Premiere Pro.
With your overlay footage selected, click on “Normal” under Mode and you will see the whole list of available blending modes:
With your footage selected in your timeline, click the inspector button to open up your video effects controls. Scroll all the way to the bottom. Under the section labeled “Compositing” you will see a “Blend Mode” menu. Simply change the blending mode to Screen.
Professional colorist and editor Juan Salvo shares a trick for creating unique overlays in Blackmagic’s DaVinci Resolve. In this quick video tutorial below, Juan suggests a better way to do this by connecting an overlay clip to your footage as an ‘external fill’ and adjusting the blending mode.