To get the picture I’m using click here.
First click your brush tool or just click B and pick out a round brush. Any round brush is fine.
Have your settings set to:
Don’t worry about the other settings.
Make a new raster layer set to screen at 100%. And now you can start using different colors on your picture. The best colors I’ve found to work with this is blue and pink.
After adding your brushes, duplicate that layer and set it to Soft Light at 20%.