This article will teach you how to competently work with portraits in Adobe Photoshop.
Steps

Step 1. First, get rid of obvious skin imperfections
The Healing Brush works best for this. Press alt = "Image" and click on the clean area of the skin (before that change the size of the brush if necessary), and then click on the blemish. Repeat on all areas to be improved.

Step 2. Whiten your teeth
Select the teeth with one of the Lasso tools and transfer them to a new layer. If you have selected extra areas, remove them with a mask. Use Selective Color Correction to remove the yellow cast.

Step 3. Using blur, smooth out the skin tone
Use the Blur tool to go over the skin without touching areas that should be clear - eyes, hair, etc.

Step 4. Give the skin a healthy complexion by adjusting the red tones with the Selective Color Correction
This will help prevent unnatural skin tones. You can also increase the saturation of the entire photo to make it brighter. Press ctrl-U (or command-U on a MacBook) to bring up the Hue / Saturation window.

Step 5. Sharpen some areas to liven up the photo
Hair, eyes, nose, etc. often look better when sharpened. But don't overdo it to avoid graininess in the photo. Use the Sharpness tool and adjust the size of the brush to work only in certain areas.

Step 6. Use the "Diffusion" filter (Filter> Stylize> Diffusion) to make the picture "softer"
Set the diffusion percentage to around 40-50% and you will get a nice picture with a characteristic "glamorous" glow.

Step 7. Duplicate the layer (Layers> Duplicate Layer) and desaturate it (Shift-Ctrl-U)
Set the blending options (it can be found in the upper left corner of the layer window) of the desaturated layer to "overlay". Experiment with the Gaussian Blur filter (Filter> Blur> Gaussian Blur), usually a blur with a factor of about 3-5 looks best. This will make the photo even softer without compromising its clarity.
