The best writing advice I can give people is to make sure your characters have hobbies.
There’s a few things I like to have when I start with a character, and it’s want, drive, need, fear, flaws, and hobbies. What do they want, (surface level, story motivation, “I want to go to X” or “I want to help Y,”) what drives them, (a deeper, more intrinsic kind of want, “I want to help people,” or “I want to be left alone;” this is usually something the character isn’t aware of, but it does tend to fuel their actions,) what do they need, (what do they need to do to overcome their flaws,) flaws, (...self-explanatory,) fear, (which usually informs the flaw; for example, if someone is scare of losing people, their flaw may be that they’re overbearing or anxious in relationships,) and hobbies.
Just. Like. What do they do for fun? What makes them laugh? Don’t go with something generic, if you can help it, don’t say “surfing the web” or “sports.” Try and find the specific niche things that make your character happy, and try to vary it up, if you can. People often like a lot of different things, or they narrow in on specific areas under broad categories. If your character likes video games, what kind? FPS games? Puzzle games? MMOS? Why? What does that tell us about them? Does your character like animals? Okay; what kind? Why? Do they have a lot of pets? Do they go to dog parks? Maybe your character likes to sing, or write music. What part of making music do they find the most difficult?
This is, in my experience, the fastest way to make someone really come to life. Just ask them what they do for fun, and they’ll more than open up.
