How can I make a Bézier curve have sharp and curved points? Like a zig-zag. And also being able to make more 'circular' parts too.
(I want to make fig 2, but I can only get to 1 by creating curves added with the E button.)
Being in Edit Mode you can select the desired curve point, press V and change the Handle Type to Vector
To have even more control you can set the Handle Type to Free
You can do this by going into edit mode, selecting a vertex and pressing S 0. This will make the vertex scaled to one single point, and it will cease to have an effect on the curvature of those segments.
The vertices are still selectable, moveable, etc.
You can change the Handle type of the selected control vertices to Vector by pressing V > Vector:
This will make the segments between those vertices into straight lines.