Make sure ffmpeg is up-to-date:
```
brew update
brew upgrade ffmpeg
```

Convert a MOV into frames. Tweak the `2/1` if you want more or fewer frames.

```
mkdir frames
ffmpeg -i screen-recording.mov -r 2/1 frames/%03d.png
```

Optional: crop the frames to 600x400px using 824,690 as top/left

```sh
mkdir cropped
convert ??.png -crop 600x400+824+690 cropped/
```

Create the pallete.gif

```sh
ffmpeg -i cropped/%02d.png -vf palettegen palette.png
```

Aaaand create the GIF. The `6*PTS` is added to slow down the GIF frames.

```sh
ffmpeg -v warning -i cropped/%02d.png -i palette.png  -lavfi "paletteuse,setpts=6*PTS" -y out.gif
```

Bonus tip: if you want the last frame to have a longer duration, just copy your last frame image a bunch of times and use new frame numbers as filename.

```sh
copy 20.png 21.png
copy 20.png 22.png
copy 20.png 23.png
copy 20.png 24.png
```

Sources: http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html