One key practice is to always focus on making the text legible at all times. There are a variety of tools within non-linear editing software, as well as other digital video editing programs, that can create amazing animated text boxes. These can be great, but it ends up being too overwhelmed with visuals and movement and can distract from its original purpose. Try to find a font and style that will be expressive toward the motifs in the film, but also will be easy enough to read.