Drawing warmups help; books, resources?

[Quofalcon]

I'm feeling a wee rusty y'all.
About a few days ago, I sat down at my art desk and was about to begin drawing starting with some of my rituals, but I thought "Nah", I wanted to try some new things. Browsing through my personal home library to find a book, I realized how much over half of my collection was about concept work and inspirational art pieces. This had me slightly agitated. I had some good instructionals and the rest were eye candy.

I've been searching for books, resources and such on drawing warmups, hoping to find something more than doodling random lines and circles. This has been an experimental goal in the past few months.

Lately I've been doing dozens of quick head sketches as warmups, but this has been getting rusty with me in the past month or so; taking me upto an hour at times.

So CA, what drawing warmups is there to offer? What do you consider best for waking up your senses? Books, online resource, anythng. Much appreciated.

-Quo

[Flake]

Paint or draw anything from life. Physical paint and/or pencil, like what exists in the real world.

Then go to a museum and see badass art (Rembrandt is usually good for an "Asskicking, put me in my place omg inspired") kinda vibe,

[HunterKiller_]

Doodling circles and lines are a fine warm-up.

Doing the really, really basic things like this is unfortunately often neglected.

I think Marko Djurdjevic said something like "If you want to draw like me, then get out a bristol pad and start drawing lines."

[Alex Chow]

I've read of a drawing warm-up from one of Bobby Chiu's books. Choose any topic, focus on it, and try this "work-out" (as he would call it):

a) Draw from another artist's perspective as if they were doing your topic.
b) Draw from photos related to your topic.
c) Draw from life; improvise and be creative if your topic is about space aliens or something.
d) Draw from imagination.

I do not do this nearly as much as Chiu suggests (he says to try this 3 times a week, 2 hours each session) but it is a great way to spark up imagination when I do it.

Of course, practice bare basics as others suggested rather than simply doing heads.

[Call0ps]

do some speed paintings preferentially from life, (e.g. your desk, your cat, your cloths on the floor, the buildings u can see from your window) i think most important is to start it, once u do something will pop up :P no need to do anything fancy if is harmup, 1 hour is enough, 2 if u really enjoying :P

[Quofalcon]

Thanks for the replies! Good posts everybody. I believe I've been a tad obsessed with the subject warmups in mind lately, and feel like I cannot begin into drawing without a simple warmup or two.
Preferring times I just sit down and get drawing, many of them I feel the need to 'stretch art muscles' or warmup the brain/eye/hand sense. Maybe I should try practicing by not starting with warmup rituals in attempt to discipline self, buttocks sit and just get drawing.