I stored all of my first son's in big bins labeled with their sizes. My mother in law loves to shop, so I have a ton of brand name Gymboree, Children's Place, Carter's, Gap, Old Navy, etc. Unfortunately, when #2 came, even though he was a boy, too, we were not able to use 1/2 the clothes because they were the wrong season when they would fit him. (#1 was born Dec 1, #2 March 22, so they've been about 1 season off through this first year.) Now we have 2x the clothes! I'm trying to store them back up as #2 outgrows a size to hand down to my younger sister when she gets pregnant. Hopefully she has a boy!
My guys are only 2 years apart, so once the sizes start to space out a little longer and only change every 6 months or so, I'll be able to take #1's outgrown clothes straight to the end of #2's closet for him to grow into and only have #2's outgrown clothes in bins instead of both like I have now. I think I need the space savers, though!!