When making a picture, it's important to watch out for tangents. Tangents happen when shapes or parts of the picture touch in an unappealing way. You can avoid this by being careful when you start your work.

There are a few mistakes to watch out for, like when two shapes overlap, when two lines touch, or when a shape is close to the edge. By keeping an eye out and avoiding these mistakes, you can make your picture look nice.

I've linked a resource that helps to visualize the world of common tangents.

Avoiding Tangents: 9 Visual Blunders Every Artist Should Watch Out For - EmptyEasel.com