1)create a copy of the layer (ctrl-j)
2)expand canvas to give room below image for reflection (This could be done after step 4 if unsure on amount needed)
4)move new layer into position below the original image
5)Create a mask for the new layer
6)Apply a black to white gradient on the layer's mask.
7)(optional) crop if needed.
I think all the steps are there. You should be a ble to find quite few youtube video on the subject.
Much appreciated. This is great!