You could give your character some unique quirks. For example, if it's a wizard, make them have a strange habit like always talking to their pet frog as if it can understand complex magic theories. This makes them stand out.
Another way is to create a distinct personality trait. Let's say your character is extremely brave but also has a crippling fear of heights. This contradiction makes the character more three - dimensional and interesting. It can lead to internal conflicts and interesting plot developments as they try to overcome their fear while being brave in other situations.
Develop a complex backstory. Maybe your character was once a simple peasant but had a life - changing encounter with a magical artifact. This backstory can add depth and make the character more engaging. For instance, they might be on a quest to find the origin of this artifact and in the process, face various challenges that shape who they are.