@ For me, creating convincing personalities and motivations is a side effect of the really useful life skill of being aware of your own emotions and motivations, and being able to observe the emotions and perceive the motivations of others.
This skill is learned mostly by practice and life experience. Some people I have met seem to be naturally talented at this, but the rest of us will have to practice practice practice!
A good exercise is to take moments off during the day and do nothing, just walk around for 10-20 minutes or close your eyes in somewhere private, and reexamine everything that happened during the day. Try to be aware of and analyze your emotions. You may feel that some of that emotions are weird, disturbing, shameful, etc. No need to feel that way. They are just emotions, thought patterns formed by a logical part of your mind and modified by your hormones, which may be related to the food you eat, your age, etc. None of this is inherently good or bad, what's good or bad is how we ultimately act.
But all of this emotions and motivations are useful to understand...
Over time you will begin to be aware of others' emotions and motivations too. The skill for writing good fictional characters will then come naturally if you like writing fiction.
Edited by citizen_lion, December 13 2016 - 07:26 PM.