1. To trim a clip, select the edge of the grey timeline and move it to the point in time that you want.
2. The keyboard shortcut to make the clip go back to frame O is option + home.
3. The keyboard shortcut to trim an inpoint is option + left bracket key, the outpoint, you do option + right bracket key. If you press I, you jump to the beginning of the clip you trimmed, O to jump to the end.
4. If you Option (Alt) double click a film clip, it will open the clip in a footage channel.
5. In the footage, you are just viewing the clip, in the layer panel, you can edit the clip and trim it.
6. The slip edit function allows you keep the in and out points the same, but start at a different part of the clip.
7. To split a layer, go to edit, and select split layer. This allows you to combine clips.
8. Stretching will allow you play a clip faster, or slower, by moving the hot text under stretch.
9. To mask objects, go to layer, and select the mode that you want.
10. To create a track mask, put the mask on top, then use the key frames.
11. A garbage mask is a mask that allows you to make track masking easier.
12. Key light allows you to change a background of a film clip.
13. To remove a green screen in AE, you need to use the key light function.
