Many techniques exist in the creation of a good story, but some of the most important are characterization, backstory, plausibility and use of perspective. If all of these techniques are employed skilfully, a story and plot naturally result. These elements of fiction writing are intertwined.
Characterization is the act of making characters seem like living, distinct personalities rather than one-note figments of the author's imagination. Characterization is shown through action, dialogue and other characters' thoughts or speech about the character. It's important to show elements of a character, not simply tell the reader.
Backstory is the technique used to explain to readers what led to the events of the present story. Backstory is inevitable, but it should be used sparingly and appropriately. Bogging a reader down in backstory can make him forget what's going on in the present. Flashbacks are another method used to establish backstory.
Plausibility is the ease with which a reader can maintain suspension of disbelief. Plausibility doesn't have to mean realism -- just internal consistency.
Shifting perspectives can also flesh out a story. Rather than use a single protagonist, the author could show another part of a story through the eyes of an antagonist or a supporting character. An example of this is the "A Song of Ice and Fire" series, which has multiple protagonists.