Personal artistic SECRETS that I wish to share with you.
You can merge them with your learned (artistic) experiences to find what's useful to you:
An exercise on letting the imagination create imageries that are actually existing in your mind's memory.
Improving the skill in drawing is more than a practice. There is a hard shortcut to it.
If you are clueless about Perspective Drawing, here is an interesting brief background about it.
An instant guide to figure drawing with diagrams in an easier to understand format.