When it comes to aesthetics, most digital filmmakers want their footage to get as close to the "film look" as possible.
Which is understandable — the look of film is beautiful! There are a bunch of factors that go into making footage look film-like and cinematic, including lighting, composition, and camera movement, but film emulators are a great way of getting the film look in post. If you're just starting out and aren't really sure about what film emulators are or what they do, this video from Charles Yeager from Tuts+ will help you learn the basics.
Film emulators do just that — they emulate film by "matching the color values of digital footage to different film stocks." Popular software and plugins like FilmConvert and Koji Color allow you to not only add the look of film stocks to your footage, but they also allow you to add film grain. They also often provide a bunch of LUTs that you can drag and drop onto your clips to get an instant look, which is helpful and quick and simple, but doesn't afford you a ton of control.
Speaking of LUTs, here is one word of warning: don't be lazy! Or — be lazy — it's your life and your film, but just know that it's really easy to let LUTs do all the work, but grading your film is a job too important to entrust to a single asset. Choosing the look of your film usually requires a ton of little decisions and tweaks, and obviously it makes things easier to just drop a look onto your clips, but it might help you to think of it as a good starting point before you add your own personal touch. (Okay, I'll get off of my soapbox now.)
What are you favorite film emulation tools? Let us know in the comments below!