I'm not quite sure how to do it but I'm sure there's a way to do so in Kdenlive: I'd like to fade out a clip to black. Could you please describe how. Thanks.

Add color clip (project three-RightMouseButton-AddColorClip),make it black. Add it to timeline, stretch and place where you need it. Add transition Luma.

Apply the brightness filter and adust the brightness level line on the timeline. Hint: double-click on line to add a key frame.

The best way to fade to black is to put a black colour clip on top, and gradually increase the colour clips opacity. Doing it the other way where you decrease the opacity of the clip on top of the black causes the video to lose some of its quality, especially noticable in slow fades.

Simple: Set the 1st clip on track 0, then add a color clip (black, obviously) below it. Then add the Wipe transition inbetween the clips, set the clip to start in the center and end in the center, and move the ending transparency bar to the right all the way. If you want the clip on track 1 to fade to track 2 then do the same except set the starting transparency to the right instead of the ending transparency. Hope I helped ;)

 i am using the composite effect to fade out to black . just add the composite effect to the part of you clip where you want to fade out . then set the transparency to 100 and select to black. next step would be to add a new point at the end and set transparency to 0. thats it