Here are a few fairly random tips in no particular order along with the corresponding Photoshop commands, though similar functions can be found in many art programs.
1) Reverse the image you’re working on to look for lines/shapes/colors that look “wrong.”
Edit> Transform> Flip Horizontal.
Work on it for awhile, then flip it back.
2) Learn keyboard shortcuts. I put them on sticky notes on my monitor until they’re sufficiently tattooed on my brain. The very first ones I learned? Cut (command X) and Paste (command V).
3) Put image into grayscale to check values.
Image> Adjustments> Desaturate or keyboard shortcut Shift-Command-U.
Does it still read well or does it turn into mush?
4) Record an Action for anything you do repeatedly that doesn’t already have a keyboard shortcut. I’ve made actions for Flipping Vertical or Horizontal, to Copy or Paste Layer styles, and now in CS4 to Link or Unlink layers (since it now is a hassle to do otherwise.) I need to record a few more Actions, actually.
5) Zoom out so the image is tiny... does it still look interesting?
6) Get ahold of a Photoshop how-to book or two, with plenty of pictures. I’m working my way through Photoshop CS4: The Missing Manual and am picking up plenty of good info. I ignore the stuff that doesn’t apply to my work flow, and put sticky notes on the pages with the real gems. Why buy a book? There are a lot of good tutorials, etc. on the web, but a book helps you to systematically cover all the basics of the program. There are many techniques that I use every day that I NEVER would’ve figured out on my own but found in a book. The WOW! series, which have even more pictures, are also excellent. There are many other good ones.
That’s it for now, just wanted to toss those out there. By the way, I upgraded from CS1, so am just now finding out about the Warp tool... love it!!! (Under the Edit> Transform menu.)
I changed my sig to have more autumn-like colors, though it’s still hot here in Florida (ugh!)