Types of Conflict
There are two types of conflict you can implement into your story: internal and external. Internal conflict is one that takes place within your character. This is often a personal issue that your character deals with, such as feeling unworthy or having trouble making a decision. External conflicts are those that involve outside influences. For instance, if your character falls in love with someone who doesn't return those feelings, your character is engaged in conflict with the other character.
Implementing Conflicts
While you only need to use one type of conflict, using both can add more depth to your conflicts. If you choose internal and external conflicts that complement each other, your character is better defined. Give your character a background that explains his internal conflict. This background leads up to the reasons why the external conflict happens. For instance, if your character was a shy child who was teased often, he will have self-esteem issues. In your story, that character may have difficulty adapting to a new job because of these issues.
Build Up Conflict
Begin your story by addressing your character's background and setting up your main conflict. Continue building upon this information as you progress through the story. It is important to throw more than one obstacle into your character's path so he can overcome them one at a time in a general progression to overcoming the main conflict. Once you are about two-thirds of the way through the story, your character should hit his crisis point. At this point, his conflict seems insurmountable. However, the rest of your story contains the resolution to that conflict to give your readers a sense of closure.
Keep It Real
The most important thing to remember when developing conflict in fiction is to keep it believable. Your readers should be able to sympathize with your characters. Keep your character's actions realistic, as well as his emotions and reactions to what happens around him. Giving your character human flaws and characteristics allows your readers to relate to your character. When your readers feel as though the conflict could happen to them, they become invested in the story.