You can enable the onion skin to see your previous and next drawings as reference.
In the Timeline view, select the layer you want to draw on and the frame in which you want to draw.
Do one of the following:
- In the Tools toolbar, click on the Onion Skin button.
In the Timeline view, click on the Onion Skin button left of the layer name.
- In the top menu, select View > Onion Skin > Show Onion Skin.
- Press Alt + O.
Onion Skin will be enabled. By default, it will display two frames before and two drawings after the current drawing.