From Ableton's Learn Live series, this short bit covers four keyboard shortcuts for creating and managing clips and scenes in Session View. Together they handle the building blocks of a live-style arrangement workflow.
Ctrl/Cmd+E toggles Stop buttons on selected clips or empty slots. Ctrl/Cmd+Shift+M inserts a new MIDI clip directly onto a MIDI track, and Ctrl/Cmd+I adds a new scene.
The most useful of the four is Ctrl/Cmd+Shift+I, which captures whatever clips are currently playing into a new scene automatically, saving you from manually grouping a working combination mid-session.