The best way would probably be to look up tutorials on the internet, there's thousands on different things you can do in photoshop. After a while, you just start to make your own decisions on subtle changes to signatures and well.. that's when you develop your own styles!
I did two more sigs in the sort of style to the previous one, but with one large easily noticeable detail..
Sprite edit of Absent v3.. WITHOUT the hood, colored stuff. Was going to add gauntlets like an LK, but they came out too bulky..
and then my first real attempt to draw something! Was testing my scanner..