would want to have an in-depth knowledge of construction. Once you know construction you should try experimenting with other ways of drawing forms, but you should never abandon construction - that's the pillar that holds up the structure of your basic knowledge of form. These other ways of learning form use your other senses to understand and record forms.
One way to do this is physical contact with the object you draw, and use as many of the senses as possible. People usually can draw the things they know best whether they are an artist or not. For example someone who does archery for a living could draw more intelligible drawings of many types of bows much better then some one who doesn't do archery for a hobby or for a living because the archer has had real experience with these objects.
Here's the first exercise to help you warn up to the idea of using the sense
of touch as a way to record forms and apply them to paper. This is hard at the start but really fun and a refreshing change from construction.
(A) Collect lots of objects into a box or bag so you can't see them. If you can get someone else to do this for you it will work best because seeing the objects first can sort-of ruin it. It would be even better if you get objects that you haven't ever seen before.
(B) Close your eyes put your hand in the box. Find one object then use your hands to feel the shapes of the object and try to work out
what it is. Try to recorded what you're feeling and commit it to memory. (C) Now put the object away (not in the box though) with your eyes still closed. Then put the box away and grab some paper to draw what you felt.
Once you've drawn it, get the object again and compare it to your drawing.