Playlists are one of the key elements in making YouTube into the ultimate music streaming service. Speed up that process by using a search shortcut.
Google Operating System points out that if you click on the three-dot icon next to an individual title in YouTube's search results, you can add that video to any of your existing playlists, or create a new one. If you're confident it's the right choice, that saves on actually previewing the video to add it. Simple but effective.
Add YouTube Search Results to a Playlist [Google Operating System]