If you say you’re going to do something, do it. When you said you would.
Meeting deadlines and following through are key aspects of feelancing. You won’t keep a client for long if you tell him a project will be finished by a certain date and time, but don’t deliver. Talent agents won’t continue to submit actors who are late to auditions/jobs or unprepared. On occasion, you might have a legitimate reason for being late. But in general, it’s essential to keep your word.
Others, who have their own deadlines, are depending on you.
I usually try to build in extra time on my end. (In Chicago, people often blame traffic or difficulty finding parking for not showing up on time. I say leave earlier.) If it’s a VO job, I can’t know if there’ll be construction in my neighborhood or a thunderstorm. Or if I’ll have an audition to prepare for/go to/submit or another job(s) due around the same time. I don’t want the pressure of having to work into the wee hours, or decide to reschedule social events because I didn’t effectively allocate my resources.
Many times, you don’t have control over all parts of a project, and have to wait until others deliver before you can. Often my contact can’t send me the script until others write and/or approve it.
Challenges arise when expectations aren’t met. For example, a client says, “I have an X minute (or number of words) VO for you that I need by Y. You’ll have the script by Z.”
I plan accordingly. But the script might arrive later than I was told. Or it’s longer than expected, which means it’ll take me longer to do. Yet in both cases, only rarely is my delivery time extended. Because my client has to pass the files on to someone higher up the food chain or to his client, who my client doesn’t want to risk losing by missing his deadline….