With my DD, we used clothespins - especially for the socks (because they're so small, they are only pinned when they are a pair, and much easier to grab)
Here's what I did:
1- Sorted according to age (NB, 0-3MO, 3-6, etc.)
I put only the first 2 sets of relevant sizes in her wardrobe (for example NB and 0-3) and kept the other stuff sorted in another closet, out of the main dressing area
2- Then, took out all of the clothes that didn't fit the season.
Reason-being, it's a shame, but a pair of shorts may look cute, but if it's for a 6 month old and your baby will be 12 mo in the summer months, there's no point in washing, taking up space in the closet, or taking off the tag. Then, you can return the item possibly, or (yes, I'll say it) regift.
3- I put together all of the "outfits" with the clothespins - I hung the shirts, and "pinned" the bottoms to the shirts, making a complete "outfit" - soooo much easier to find things.
As DD gets bigger and clothes are less matchy-matchy, pants get pinned to a separate hanger, then when I'm ready to plan her outfits for the week, I match-em up, and pin the outfit. Saves a TON of time in the morning.
4-Last, for the sleepers, onsies, bloomers, blankets - they all get folded.
Hope this helps! DD is 3 now, and this system still works for us :)