Can you also deliver alpha channels and masks?
A technique for commonly used for background removal of more "difficult images"?
First of all, we need to define "difficult images". Generally speaking, these are images with either a complex background (not plain) or subjects with complex shapes like strays of hair or products with many small details.
In these cases, we apply the use of alpha channels and masks. This means that we don't create a clipping path around the subject and simply remove the background. We make a rough selection of the subject by using several methods (color selection, quick selection, etc.) and then we carefully remove or keep any matters using the mask.
Note: in general this technique is more complex but very efficient and used more often then one might think.