Allow for a little space in your unit. Cramming reduces airflow, which can lead to molding and poses a fire risk. Opt for the next size unit if you think you’ll end up cramming things together.
Don’t let your unit look like the one in the photo above. Make sure to leave enough room for you to get to items in the back, and keep items you get to often in the front. Try adding some shelves or storage boxes for more utility.