I've heard some say that all writers need to be historians so that they can enrich their writing with fact or have a strong basis for events. To know an event is to know every event based upon it. The same goes for characters, places, battles, disagreements, and so on. But I much less often hear someone talk about legend, let alone mythology. These two wealths of knowledge and, more importantly, story and character structure, can greatly help many writers, but they often seem unfocused on or overlooked.
Legends and myths are an important well to take from, creatively speaking. They provide rich stories with strong characters that helped them last the ages. You've likely heard a legend or two -- King Arthur and Robin Hood being quite popular ones. Legends are the link between history and mythology; they're stories that may have some truth in them or be close to historical truth, but cannot be verified. Mythology is creativity at its finest. Myths about almost anything have been around for ages. Additionally, each culture has their own version or twist of common myths or have their own specific tales that are singular to that culture alone. You can see that there's a lot of content to work with here.
When it comes to using content like myths or legends as a basis or a guideline or just as inspiration, some will call the work derivative. Derivation is not petty or unskilled. A derivative work is only bad when executed poorly, just like any other form of a work. The key is to use legends and myths as creative and inspirational filler. Take Tolkien's, "The Lord of the Rings." Many of the character names are exactly or derived from Norse mythology. In fact, almost all of the dwarves from "The Hobbit" take their names from a section of the Poetic Edda. Gandalf's character is based on the popular portrayal of Odin as a wise old wanderer with a staff, a wide brimmed hat, and a cloak. Why try to make up dwarfish names when some already exist? Why create a new mysterious and powerful wise man when one is already brimming with content? Tolkien used his mythologies and legends well, just by simply cherry-picking what he needed and using it skillfully. What's important is to not get carried away and have your work become a copy.
Using myths and legends adds depth. If there's one thing readers like it's understanding a text on multiple levels or finding hidden meanings. This depth can answer questions, cause intrigue, and gives a piece readability. Why does the author include this? Why here? What's this name mean? What does this tell me about a character? These are all questions that a writer can answer without stating them explicitly. Here's an example:
Mine kin keeps on and keeps on, killing the Saracen serpents hiding so like snakes in sand, pleasing palace potentate to points of princely reward. And so Constantine is constantly capturing me in my greed. Gold glows like Surt’s sword at the very end, flowing from chests, my eyes do see the frightening truth; like Fenris thou hath been chained by simple silken shine.
As you can see, I've made some references quite obvious (using the names Surt and Fenris). But, some of the themes don't quite mix on the surface level. Let's go through this logically. The person speaking has a greater knowledge of Norse mythology, referring to Surt and Fenris and their respective tales ("at the very end" referring to the end times, and "chained by simple silken shine" referring to Fenris' myth). So, it stands to reason that this person is Nordic. He also mentions Saracens and Constantine. Saracen was a common medieval term for Muslims used especially in Byzantium/Constantinople -- thus explaining why Constantine is mentioned. Why is a medieval Nordic person being given treasure by Emperor Constantine for killing Saracens? Well, the Vikings were enlisted by Constantine as his personal guard. This is just a small portion of a piece I titled "The Varangian," the name being derived from what these Vikings were called the Varangian Guard. Here, context makes sense for references to mythology and legend, but the way I use it is to describe. Without the two references to mythology, the gold is not as lustrous and destructively inviting nor as entrapping and torturous. It adds depth of emotion and a different understanding of the character without saying such things directly.
The one takeaway from this that I want to make clear is that doing this can take time. The example I gave is simple and straightforward, but to interweave and spin a web of deep lore that has an inspirational basis in legend or myth is hard to do. But that is what makes them worth the doing. Rather than a surface level for the reader to absorb and forget about, you allow a greater realm of re-readability and analyzation. All writers should have a basis of myths and legends that they can refer back to, use as guidelines, add depth with, or simply find the right name or character they need.
Keep it legendary, my friends.