I use Cyberlink Power Director, myself, but that costs $$ and only works on Windows.

I use Cyberlink Power Director, myself, but that costs $$ and only works on Windows. This is open source (free) and will work on Win, Mac, and Linux.  It looks like 2.2 has some really good improvements.
http://www.openshotvideo.com/2016/12/openshot-22-released-4k-video-editing.html