I recently fell down a Pinterest hole and found a bunch of these super helpful subplot tips, so I decided to share the best of them.
- Not everyone should love the hero
- The more antagonists you have, the more conflicts you create; and bonus points if the antagonists don't JUST hate the protagonist, but also don't/do get along with some of the other antagonists.
- Real life should happen to the characters, even if they are saving the world they have jobs and responsibilities. After saving the city, somebody has to wash their super suit and pick up milk and butter from the grocery store. Saving the city doesn't pay the water bill either.
- Give the character interests and friends outside of the main focus of the story. They're a hardcore magic duelist yeah, but they also like going home and read a book after a bath. Vice versa, they may be a genius alchemist creating a potion that will win them the wizard king's contest but they also quite enjoy playing magic sports.
- Multiple POV's aren't a bad thing if you know how to juggle them. Oh, the shenanigans you can pull with a well placed POV. ;)
- Not every antagonist needs to be vanquished in the end.
- Give us more than on character to love. -- (from Diantha)
- Make each and every character count. -- (from Diantha)
Non-romantic and non-sexual subplots:
- Bonding with a small child
- Reconciling themselves to a family secret
- Overcoming a phobia
- Finding/building/decorating/creating a home
- Realizing a best-friendship has developed
- Establishment of a new traditions (spaghetti Tuesday, every Wednesday. lol)
- Long-running competition or rivalry (Naruto is a great example of this)
- Learning a new skill
- Coping with a mysterious ailment
- Adapting to a recent disability
- Fighting an eating disorder
- Crafting a masterwork
- Preparing for/taking a long trip by themselves or with others (Bilbo's journey in the Hobbit or Frodo & Sam's in the LOTR)
- Taming a wild or feral animal
- Training a new pet/work animal
- Finding a new job
- Having a faith crisis
- Getting lost and discovering something they shouldn't have; I.e go searching for potion ingredients in a remote place and accidentally discover a tomb instead, but the plant they need is growing on the mummy so now they have to figure out how to remove it without damaging the corpse. (Or just straight up not caring about ruining the crypt because their potion ingredients are the only thing that matters. No one has to know.)
- Making an unlikely friend in an unlikely place.
These are all well and great but the thing you need to remember is that it all needs to come together in the end.