Tap the pencil icon on the Preview screen to draw and doodle on your Snaps. Use your finger to draw, and tap the back icon (right arrow curving left) to undo.
To get a little more creative...
- Resize your brush by pinching your fingers in and out
- Change the colour of your brush with the colour slider
- Change the colour palette by tapping the colour overlay icon
- Draw with emoji by tapping the emoji button beneath the colour slider