I absolutely love these packing cubes. They really help to maximize your space when packing luggage. I use these slim cubes for underwear and socks, mainly, and can fit 12 pairs of socks or 10 pairs of underwear per cube. The socks, I fold regularly but the underwear, I fold 8 pairs vertically in half then roll up nice and tight then lay 2 pairs folded regularly on top. I'll never pack without these again!

(P.S. If you've seen my reviews on all these different sizes, yes, I copy/paste the main text but I change any relevant information. I'm not just spamming, I swear, lol!)