When you draw, you can tilt your Apple Pencil to shade a line. Choose from several drawing tools and colors, and switch to the eraser if you make a mistake. Double-tap the eraser to view erasing options on your iPad. You can also start by tapping to open the tool palette. Made a mistake? You can erase by object or even by pixel. Use the ruler tool to create straight lines, then rotate them with your fingers.
The tool palette has different tools, depending on the app you're using. With iPadOS, move the tool palette around the screen or minimize it so you have more space to draw and sketch.