A useful benchmark for character creation is to orient their initial design around being relatable, eccentric, or in some way mysterious. Over time, a character can grow to become more distinct, but these three starting personalities will help ensure that the final result of a character’s design is interesting to the reader.
Mystery can be created by giving the character an unexplained past. A character may have spent time in jail; been dismissed from the army; endured some trauma, physical or otherwise. Mystery can then be made more explicit by having other characters wonder about it.
Mystery always attracts the reader’s attention by evoking curiosity and anticipation, two major storytelling emotions. (Writing for Emotional Impact, Karl Iglesias)
Eccentricity can be established by giving a character an excessive behaviour, such as being overly passionate about something or having their emotions pivot between extremes.
(…) it’s our nature to be attracted to what’s different, to the unique, anything that raises our curiosity and makes a character fascinating is an effective way to maintain the reader’s interest. (Writing for Emotional Impact, Karl Iglesias)
Creating a relatable character is trickier, as relatability can easily become more mundane than interesting. A helpful tip for crafting an ordinary yet engaging character is to give them qualities the reader would aspire to themselves, such as confidence, determination, effective leadership, courage, etc.
It’s our nature to like what’s like us and fear or distrust what’s not. So we can identify with a character who shares our values, opinions, and attitudes. When we see our hopes and struggles, the qualities we have or wish to have, we recognize their humanity with our own, and thus experience their emotions vicariously. (Writing for Emotional Impact, Karl Iglesias)