All you need is a pair of jeans , a fabric marker and an iron Just as seen in the photo below
Fabric marker is a permanent marker that you can use on fabric. When the ink dries you have to fix it on fabric with your iron at medium heat.
Decide where to draw the leopard print, and start drawing your design. You can put some spots around too. Look at the photo, you would observe the leopard spots someones are closed others are open.
To draw the leopard spots you can draw a c and make it fuller in some parts like this. Then let the ink dry. When it is dried, Take your iron regulated at medium heat and press it on the jeans holding it on the drawing to fix it on the fabric.
After all this is done you can wear your jeans