I work in a densely populated downtown area, therefore I double park all day every day.
Put your hazards on and if you can, get a cone from your building and place it behind your package car when parked. Pull in your mirror when you stop so no one hits it going by. Most people understand you are working and there isn’t a parking spot for that giant package car. For the rare occasions someone gets mad at me for double parking, I just laugh and ask them if it looks like I’m parked here for fun? Do they have a better suggestion for me to park this giant truck?