Tutorial #1: Whitening teeth in Photoshop.

1. Change the yellows in the photo using adjustment layer to white and change brightness.

2. Create composite layer by pressing shift+opt+cmd+e.

3. Use spot healing brush to fix areas that need to be fixed.

4. Use brush with same color as teeth and low opacity to fix remaining areas.

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After

Tutorial #2: Changing eye color in Photoshop

1. Make a selection around the eyes you want to change.

2. Feather the edges of the selection.

3. Desaturate the eye selection to a medium gray so that they accept the new color using a black and white adjustment layer

4. Add either a solid color or a gradient adjustment layer.

5. Pick a color.

6. Clip the color to the eyes underneath by opt+click.

7. Change the blend mode.

8. Clean up the eye using the layer mask.

Before

After