Normal, Oily, Dry, Combination, and Sensitive.
People with normal skin types who do not have any chronic skin conditions can have both chemical and mechanical exfoliation will be safe and effective. The choice depends on personal preference.
Oily skin types will benefit most from mechanical exfoliation. While using a brush or scrub is less effective in removing built up oil. If using a scrub, apply using the fingertips in a small circular motion. Brush users should stick to shorter or lighter strokes.
Try to not use mechanical exfoliation on dry skin, because it can dry it out even more. Glycolic acid will help get rid of dead cells. Use an SPF and moisturise after using glycolic acid.
People with combination skin often benefit from doing both mechanical and chemical exfoliation. Combination skin types should not mix both exfoliation types in the same day. Instead specific days of the week should be designated as mechanical or chemical, often with a rest day between. Make sure to use a high-quality moisturizer if the skin feels dry after exfoliating.
Sensitive skin types need to have a chemical exfoliation as most mechanical methods will cause irritation or redness. There are a lot of great mild chemical exfoliating products in lower concentrations that will exfoliate the skin without damaging or drying out the skin. Make sure to apply lightly with a gentle washcloth. Exfoliating once a week will often provide the most benefit to sensitive skin types.