Well if the thing you need to draw for isn't too high stakes, one way to sort of cheat and get good fast at drawing is to simply trace existing drawings. Practice by tracing the same thing multiple times then see if you can draw it without tracing. You can still look at the object as a reference and in fact, this is the proper way to learn how to draw stuff. I don't recommend tracing if you actually want to be able to draw well, but it can help you pick up some drawing basics in a sort of sloppy and quick way. It will at least get your hands used to the motions and force you to start seeing the shapes that form together to make the object of your desire. I can't help you if you need any shading or coloring though.
Source: Me who dropped out of an animation degree after realizing that quick doodles don't make a career. Take my advice with a grain of salt.
