I usually make my patterns on a computer, then print them out, glue them on cardboard and then laminate the underside of the cardboard with a clear plastic laminate sheet, and cut them out. I then spread a thin layer of leather glue on the laminate side of the pattern using a canvas covered squeeze bottle. (a bit of canvas over the mouth of the bottle and rubber banded in place around the throat of the bottle. (make sure to cap the bottle after every use or the canvas becomes clogged) When tacky, I stick the pattern to the grain side of the leather I am cutting, cut out the pattern, then pull the pattern off. This helps keep the pattern in place while cutting.
When I finished cutting, I remove the pattern from the leather. I then use baby powder applied to the laminate side of the pattern to neutralize the stickiness on the pattern, and place the pattern in a plastic sleeve, which allows me to use it again later.
I've learned the hard way though that the glue must be a very thin coat and you must wait until it is tacky before sticking it to the leather. Othewise you will leave glue clumps on the leather surface which can sometimes be a bear to remove.