Turn any photo into a dot grid artwork with these Photoshop actions. You'll get great results with dots that change size. They get larger in brighter areas and smaller in darker areas. Free download available.
Learn how to do vibrancy masking in Photoshop. You’ll learn how to increase saturation with the Channel Mixer and then use Vibrancy masking to control whether you want it to affect the vibrant or non-vibrant areas. This technique works amazingly well for landscapes and it’s a great when you want to get the most intense and vibrant colors you can from your photo.