Like many other artists, I have issues with compounding and converging curved objects that have more than 2 dimensions and are viewed at certain angles. These are the curves like those that make up the hull of a boat, certain leaves, and quite a few other shapes.
While you can extensively map out the shapes in many planes using constructive methods along with intensive use of 3 (or more) point perspective that is only practical for when you actually have a good idea of what the shapes already are, or have solid reference. Instead I’m finding that many plant structures, specifically buds and leaves, give you great reference to learn from and build up a shape library from. You can quickly sketch out the forms and build up the shapes that should later allow for more fluid and natural shape exploration.
One of the things that makes them ideal is that with in one image, you can capture essentially the same form from a number of angles and scales. You very naturally have what would take many photos worth of reference then combined into a mosaic type reference sheet in one go. With a little creativity it’s not hard to imagine a succulent leaf or bud becoming a helmet, an airplane wing, the new seat or back of a chair or many other objects.