Sure, here's a step-by-step guide to retouch and enhance portrait images:
1. **Open the image**: First, open the portrait image you want to work on in an image editing software like Adobe Photoshop or Lightroom.
2. **Cull and select**: If you have multiple images, choose the best one. In Photoshop, you can use the Quick Select Tool or Pen Tool to select the subject if you need to make precise selections.
3. **Adjust exposure and contrast**: Start with basic adjustments to enhance the overall look of the portrait. Use the Levels or Curves tool to balance the exposure and contrast. Increase the mid-tones to make the skin look more vibrant and reduce the highlights to prevent any blown-out areas.
4. **White balance and color correction**: Use the White Balance tool to adjust the color temperature to make the skin tones more natural. If necessary, use the Color Balance tool to correct any color casts.
5. **Skin smoothing**: For a natural look, use the Healing Brush or Clone Stamp to remove blemishes, freckles, and other minor imperfections. For more significant corrections, use the Frequency Separation technique, which involves duplicating the image, applying Gaussian Blur to the copy, and painting back the details from the original.
6. **Eye enhancement**: Brighten the eyes using the Dodge tool or a curves adjustment layer. Remove redness and any discolorations around the eyes with the Healing Brush. Optionally, add a vibrancy mask to the eyes to make them pop.
7. **Teeth whitening**: If the teeth are not already white, use the Hue/Saturation tool to select the teeth and increase the Lightness value slightly. Be careful not to oversaturate them.
8. **Lip enhancement**: Use the Brush tool with a soft edge to apply a slight increase in saturation to the lips for a more vivid color. Adjust the hue if needed.
9. **Remove flyaways and stray hairs**: Use the Healing Brush or Clone Stamp to clean up stray hairs and flyaways that may be distracting.
10. **Slimming and reshaping**: If the subject needs it, gently slim the face, neck, or other areas using the Liquify tool or Free Transform. Always aim for a natural look.
11. **Facial structure**: Use the Dodge and Burn tools to subtly enhance the facial structure by adding shadows and highlights. This can help define the jawline, cheekbones, and other features.
12. **Skin tone and color correction**: Apply a Color Balance or Hue/Saturation adjustment layer to the skin to correct any color casts or to give the skin a consistent tone.
13. **Spot healing**: Address any additional spots, blemishes, or distractions on the skin with the Spot Healing Brush.
14. **Highlights and shadows**: Add depth to the portrait by using the Dodge and Burn tools to add more highlights and shadows to the skin, hair, and clothing.
15. **Dodge and burn**: Refine the light and shadow areas to create more contrast and definition in the portrait.
16. **Sharpening**: Apply a high pass filter or use the Unsharp Mask to sharpen the image. This is particularly important for the eyes and other areas of the face.
17. **Skin softening**: Apply a softening filter like Gaussian Blur or use the Soften tool to reduce the appearance of pores and fine lines without losing the texture of the skin.
18. **Adding a vignette**: Optionally, add a subtle vignette to draw attention to the subject by darkening the edges of the image.
19. **Noise reduction**: If the image is noisy, apply a noise reduction filter like the one found in Photoshop's Camera Raw or use a dedicated plugin.
20. **Final touches**: Look over the entire portrait and make any final adjustments to ensure that the overall lighting, contrast, and color are pleasing.
21. **Save and export**: Once you are satisfied with your retouching and enhancements, save the image in the desired format and resolution for the intended use (e.g., web, print).
Remember to be subtle with your changes and respect the subject's natural features. The goal is to enhance the beauty of the portrait rather than alter it drastically.