Smooth curved lines
Would be awesome to be able to draw curved lines with many curves (concave, convex). The feature should allow the user to draw the line roughly with the apple pencil and smooth out the curve to make it look good. This would be similar to the "free-form" feature in Microsoft Visio.
An example of such lines is shown in the attached PDF.
Thanks :)

-
Madelyn Lubinsky commented
This would be an AMAZING feature for science and engineering students as well. There are many symbols I have to draw regularly that would be much nicer if they were automatically made to be neater, such as an integral symbol or different types of curves when graphing.
-
morgan hughes commented
if we could snap to shape other types of curved lines like these that would be do helpful when taking notes and drawing diagrams like mind maps!