Hi Kosmo! Good to have you around!
Character development is something that comes with getting to know your characters in detail. That can be a difficult thing to do by yourself, but maybe the Character Clinics here can help you with that. You create a thread from the point of view of your character, and members ask the character questions, which you answer from their point of view. This might help you give them a little more depth. I know it helped me tremendously in developing my novel. It might be worth taking a look at
Also, something that might help in developing your own writing skills, is to critique the work of others. By reading pieces by other members and critiquing their dialogue -- what was good, what was less good and how can that be solved? -- you learn how to look more critically at your own work and make it better in the process. Plus, you get to know members around the boards!
Have fun, and I hope to see you around! Grab a cup of crunchy tea and a lollipop