On the wiki, the Intelligent Lifeform Index lists 188 different species that are permitted for player characters. This list includes the usual suspects like Humans, Vulcans, and Klingons. There are also plenty of species who only made a single appearance anywhere in any Star Trek series. Species original to Starbase 118 like Laudeans are also on the list. New writers have no shortage of choices when it’s time to pick a species for a character. But how can you narrow down so many choices to one?
A species like the Vulcans have a large collection of source material that can be drawn from. Decades of existing in the Trek universe have made the Vulcans very well-established. Meanwhile there are species that have little more than a name. The history, characteristics, and cultures of a species can influence how we write for our characters.
What helped you decide which species your character would be? Each species that you could choose makes a character unique and brings something unique to the table. A well-developed species with a rich history and culture provides plenty of material that can be used in sims. Meanwhile, helping to flesh out the worlds and customs of a less-explored species like the Bolians or the Deltans can be just as fulfilling. There is no right or wrong way to decide which species your character should be.