I think most people struggle to draw from imagination, not the least when drawing figures and using construction can be a challenge
Sometimes it can be a mind frame problem. You may be frustrated but inspired, doodle something super quick and when you dont like the outcome get more frustrated - it can be a painful spiral, one i am familiar with
I say there’s no need to stop doing doodles, doodling and experimenting is all mileage and leads to comfort within the medium of choice, so doodle away. But… for better results - doodling is not enough. You need deliberate practice. If you really want to take a swing at drawing something from imagination, dont reinvent the wheel - try your hand at one of these that i have learned of or try something else (i aint no expert!) but dont only doodle and expect to “get there”
Option A: imagine something, try visualizing and articulating the main idea and even details if possible. Then make small sketches, thumbnails. Then choose the one or two you like and make a bigger sketch or two or ten until you iterate to get to a general composition you enjoy. At that point you will want to study references to make a more finished sketch, then refine and work on it until you are satisfied. Depending on your choices you may want to first study and copy things before attempting your own
Option B: deliberately work on enhancing your memory based drawing. You pick an object in life, draw it with construction and try drawing it in different angles or perspectives and try to memorize it, then iterate on it from memory. A constant practice that lead kim jung gi to be one of the most prominent draughtsmen capable of making finished pieces in ink from imagination while using perspective in masterful ways. In interviews he would talk about his sketch diary and how he would study objects by observing and later in the day draw them from memory in different angles (crumpling pages and throwing away any failures in frustration) also note it took this dude more than 20 years to reach his level of mastery not overnight
Cheers!
