Manipulating nails by increasing length & changing shade

Start by opening an image of hand with short nails.

Create selection of the nail using polygon lasso tool. Press Ctrl+J to copy paste the selection in a new layer.

Duplicate the layer. Move this layer a few pixels upwards and left.

Select eraser tool with soft brush settings and remove the right edge. Select and merge both the layers.

Similarly create increase other nail's size.