>>7700730
Use your pencil as a straightedge to check what should align with what, take rough estimates of angles, and measure things. If you can, printing out the reference will make it easier when drawing traditionally but you can still do it with digital reference when drawing trad, it's just annoying.
You'd probably benefit from doing some line control practice as well, the wobbliness of your lines isn't doing any favors for your accuracy especially on the long prism.