Lossless Cut is probably the simplest way to cut out parts of a video without having to re-encode it or use an online service. It is open source, free and available for all platforms. It is in essence a frontend for FFMPEG and cuts without re-encoding, so the results are instantaneous.

VideoTap has an amazing feature called Clips, which allows you to highlight parts of the transcript of a video to create shorter videos for social media posts. I got my team on it, but as you pay per minute of converted video it would be wasteful to upload a one hour talk to create a few 15 second videos. So I was looking for simple tools to use and Lossless Cut came up.

Here is how to use it:

1. Download the version you need for your operating system (there are free links to installers, but if you want to support the project, you can also download a $20 version on App Stores)
2. Scrub to the part of the video you want to start cutting a part from
3. Press I (for in)
4. Scrub to the end part
5. Press O (for out)
6. Hit the export button

I love that the tool doesn't re-encode and supports keyboard shortcuts. Another open source alternative for this task that has a lot more features is Openshot which is purely mouse and context-click driven.