Most menu commands also have shortcuts, normally using modifier keys (shift, control, option, command). Almost every tool has a shortcut key, no modifiers required. Once you know the most used keys, you’ll become much faster. V, B, M, D, X, Q, command-I, command-shift-I, command-A, and of course command-S. Another big one is to command-click a layer, channel or path thumbnail to load it as a selection.
apply all kinds of masks
A mask is an channel-based representation of a selection, usually controlling which parts of an image are visible. A selection is rough; the “marching ants” only show you the parts of an image that are 50% selected or greater, but a mask will show you more subtle information. Masks mean you’ll never (well, 99% never) use the Eraser again. Quick Mask (simply press Q) converts a selection into a mask, and is the easiest way to convert between a selection and a channel. Once you’ve made a selection (perhaps using Quick Mask) you can convert it into a Layer Mask by pressing the dedicated button at the bottom of the Layers palette. Why is this so important? When you use the eraser, you’re not only setting the opacity of a pixel to 0, you’re effectively clearing whatever colour information was once there — because there’s no “uneraser”. When you erase by painting on a layer mask, you’re only setting opacity to 0. A quick press of X to reverse black and white means you can paint the layer back in. Also very handy is the Clipping Mask, using the transparency information of one layer to define which parts of the layer(s) above are visible. Option-click between two layer thumbnails or choose Layer > Apply Clipping Mask.
definitely use smart objects (and smart filters)
As of CS3, Photoshop lets you do wonderful things with Smart Objects. Any number of layers can be converted into a smart object — essentially, a document within a document. A double-click on the smart object in the Layers palette opens it as an embedded document, much like an option-double-click on a placed InDesign document in InDesign. The joy of CS3, though, is that you can apply filters (and the Shadow/Highlight adjustment!) directly and non-destructively to Smart Objects. Especially powerful when you resize an image for web and find your sharpening adjustment is still appropriate.
use adjustment layers
Don’t ever use Image > Adjustments unless you’re editing masks, you’re using Shadow/Highlight on a Smart Object, or you’re using a strange adjustment that isn’t available as an Adjustment Layer. Plain adjustments are destructive and of poorer quality than using Layer Adjustments. Why? Every time you apply an adjustment, you change the pixel values in your image. If you use Image > Adjustments, any fractional numbers in the result (very common) are rounded off. Adjustment Layers, though, are all applied in one pass, then the final result is rounded off — crucial if you use multiple adjustments, such as Levels + Curves + Hue/Saturation. Much higher quality, built-in masking, and far more flexible as you can edit and re-edit their settings indefinitely. Finally, one of the inconveniences of Adjustment Layers has been dealt with in CS3 — cloning and healing can be set to ignore adjustment layers entirely, avoiding “double-adjustments”.
respect your image
I don’t mean to get all floaty and nebulous, but remember not to push your image too far. If you’re not careful, if you use destructive adjustments, if you don’t use new layers for each change, if you don’t avoid clipping, if you push your image too far in Camera RAW… your image will suffer. Take the best image you can, and use the image itself to provide your selections, through channels. When you’re retouching, put all your adjustments on separate, new layers, so you can selectively remove parts of your image. And please, please, try not to make everyone totally “perfect”. We’re not, and it makes your job harder. Retouching, like any lie, is easier to pull off if it’s close to the truth.
use a graphics tablet
Because you can’t paint a mask properly without one. Clipping paths are easier too. A tablet can be good for avoiding RSI, as it adds variety to your arm movements. A tablet also lets you make fuller use of Photoshop’s brushes, but note that if you’re painting straight lines (common when touching up masks) you’ll actually want a non-pressure sensitive brush to avoid creating comets. Fancier tablets allow you to change brush characteristics based on brush pressure, angle, rotation and more. Cheaper tablets only recognise pressure, though they do come with a built-in pen holder.
know your brushes
First off, brush heads are very useful (and you can make your own) but the basic brushes are most flexible. With a normal circular brush selected, use the square brackets [ and ] to change the brush size, and shift-square brackets to change its hardness. When that’s not enough, remember that there’s a big difference between changing the brush preset and simply changing the brush head — you’ll miss all the pre-built changes in scattering, colour, shape and other dynamics. Scattering is often useful, as is random brush head rotation on natural media brushes. Also remember that brushes aren’t just used by the brush tool; the Art History and Smudge tools can use good brush presets to great effect. Finally, if your brushes are stuttering, lower the Spacing value.
dodge and burn to clean masks
When touching up masks, it’s natural to use the brush tool to paint in black and white. Be careful the brush isn’t too hard or soft (shift [ and ] ). That said, if you need to clean up the edge of a mask, the brush is the wrong tool. Set the dodge tool to work on highlights and the burn tool to work on shadows. Now you can paint as close as you like to the edges of a mask with ease.
use fullscreen mode
Often you need to work on multiple files at once, to drag between them, to compare one file to another. But if you don’t and you’re clicking anywhere near the edge of a file, full screen mode gives you the ability to click near the edge of the canvas with a large, fuzzy brush. Focusing only on the image (f, f, tab) also gives you the ability to ignore the interface, to ignore your desktop background, to become one with the image. Om.
make friends with RGB
Yes, if you’re printing, you’re printing in CMYK. But very likely, the image originated in RGB. CMYK is an output format, and if you do all your colour correction in CMYK, you’re missing out on the greater colour gamut (and thereby quality) of RGB. Every output device is a little different, and leaving an image in RGB as long as possible will maintain higher quality on a wider range of devices. Make sure your colour profiles are accurate, and use RGB for as long as you can. If you need to perform final adjustments in CMYK, go for it, but keep your fully-layered RGB file too.