Bad Snacks demonstrates two Ableton MIDI editor features that make melody writing less intimidating: Scale Mode, which locks the piano roll to C major so every note you place is in key, and Draw Mode with eighth-note grid snapping for quickly sketching rhythmic figures.
The deeper takeaway here is a general composition principle: repetition legitimizes. If you land on a figure you like, even one you stumbled into randomly, repeating it signals intention to the listener. What sounds accidental once sounds deliberate twice.