Let's say that to select an object from a photograph, I create an approximate shape with the Pen Tool so that it consists of sharp corners.
Then, with cmd-click, I drag each anchor point to a more precise spot so they really are where I want them (along the outline of the object).
Last, I just drag the handles either symmetrically or asymmetrically to crate the curves I want.
Okay, I do get the work done. But what's always baffled me is the logic of how the handles work; to bring the handle visible and start adjusting the curve, you have to drag it, usually somewhat along to the direction of the actual path if the point is to smooth out the sharp corner.
Sometimes when you do that, it goes as expected, but sometimes it makes a 'knot' so you'll have to rotate the handles 180 degrees around the anchor point to straighten it. What's the logic behind this, how can I know which direction to start pulling in order to avoid this unpractical knot? Here's an illustration.