I consider the purchase of my label maker a rite of passage. On the day it was brought into my life, I passed from organized young lady to professional organizer. I had, obviously, been labeling things for years. A Sharpie does the trick on most surfaces and I was easily able to differentiate between the container with my school supplies and that holding my old birthday cards. But the label maker made this all more...beautiful.
Whether or not you're looking to invest in a good ol' maker, labeling is essential for organization. To be able to open up a storage closet, see what's before you and know exactly where everything is BECAUSE IT'S CLEARLY MARKED. The first step here is to figure out general categories for what lies before you. What makes sense to store with what? Should I keep my beach balls in the same box as my holiday decorations? (Spoiler alert: NO! That makes zero sense.) Separate your belongings based on how often you use them and then for what purpose you use them. Once everything is (neatly) put away into storage containers, grab your Sharpie or LABEL MAKER (!!!!) and slap on a code word. Something that will alert you as to what exactly is in the box. Don't be afraid to generalize here. No need to list 'toothpaste, dental floss, toothbrushes, old dentures...' A simple 'Dental Care' will do the trick. Now when your floss runs out, BAM!, you know just where to find more.