1. Avoid sharpening before you retouch, but clean up the colours in Levels and Curves before you start retouching. Good colour correction will also make the image look sharper in a natural way.
2. Always retouch on separate layers, leaving the Background intact. The Background layer below serves as a safety-net if the retouching really goes wrong, but more importantly, lets you see the before-version at any time.
3. Avoid achieving excessive perfection in one area at an early stage of retouching, because you might commit yourself to a high degree of retouching in the whole image, which will often cause the image to look totally unnatural.
4. Work on the skin first, because this will help you avoid layer conflicts later. The skin can be regarded as a canvas, and the features can be treated as separate elements to focus on later. While you work the skin, you also get the chance to get to know the face, and note the other things that need to be refined.
5. Don’t forget to retouch the area between the eyebrows and the eyes and also the area between the nose and lips, and transition between hair & skin.
6. Eyes can usually take a bit extra contrast and brightness. This doesn’t mean that you should brighten only the whites. A well-designed Curves adjustment for the whole eye will usually do the trick.
7. The difference between the Healing Brush and the Clone Stamp Tool may seem subtle as you work on skin, but is actually quite major. The Stamp Tool simply clones one area onto another (with a hard or soft edge and a chosen opacity). The Healing Brush is great for cloning texture.
8. The Healing Brush often bleeds when you heal close to a contrasting colour. Try using the Clone Stamp Tool in these cases, or learn how to refine your technique. Cloning & healing with too much repetition is the most typical retouching mistake. Breaking up subtle gradients in the background or skin when using the Stamp Tool can often be avoided by switching to the Healing Brush.
9. Using the Blur Tool on blemishes simply does not work! Blurring is something that should be applied heavily – usually as a filter – and used only very lightly.
10. While you do want to work in Layers to give you a safety net and stay in touch with the original, you may find that layer conflicts can occur towards the end, when you want to work on a joined-up layer. You may have to merge everything into a new layer on top of your layer stack, for the finishing touches.