Image Enhancement - basics

original image

1. open the image
2. duplicate layer (ctrl j)
3. set the duplicated layer to overlay

duplicated layer set to screen.
screen is used to brighten dark images.

2 duplicated layers. first at screen second at overlay

duplicate layer. filter>sharpen>sharpen
set layer to overlay

remember, if you think the property is a bit too intense, lower the opacity of the layer. play around with the other layer properties!
you can also create a new layer and fill with a gradient/texture/solid color and change the layer property for a cool effect.