Listening
By having "good ears," you can capture all audible English speech and important sounds that are relevant to a video's storytelling. Paying close attention and listening to all the audio will help ensure that the resulting captions are complete and accurate.
Research
Google can be a captioner's best friend. You may find yourself captioning an audio file that contains unfamiliar words, proper nouns, or phrases that you are not familiar with. A quick internet search can make sure that you are using the correct words and terminology.
Attention to Detail
Every great captioner knows the importance of proofreading. By reviewing your work before you submit your captions, you can check to make sure that the captions are accurate and read clearly, include correct placement of captions to avoid covering text in the lower third, and accurate syncing to within a 1/2 second to the start of the audio.
Adherence to Style Guidelines
The most successful captioners refer to Rev's style guide and accompanying Help Center articles often, and use available resources to continue to improve in their speed and accuracy. This may include practicing in the sandbox version of the Dash, Rev's captioning editor, and creating text expanders, which help to accelerate the typing process.