Then, right-click on them and choose Convert to Smart Object. Select the top layer and the white layer.Add a white solid color layer in between the two layers that you currently have.Then, use a layer mask to hide all the areas that you won’t need in the final picture and use a soft edge brush to erase the hard borders of the subject. Then paste (as a second layer) the image that you want to turn into a sketch. Start with a base photo of a sketchbook.