My church has a two big consignment sales every year. This week the Fall and there's another one in the Spring. If you have ever sold in a sale before, then this is a lot of work. Our sale is computerized, so you have to enter in the item to the online system and then print out a tag and pin it or tape to each item. A lot of work. But that brings us to this topic which is clothes for your kids. We have saved so much money by clothing our kids from consignment sales. Lets face it. Kids don't stay in clothes for long periods of time anyway. You can find great deals here. For example: we are selling a swing that we purchased at a consignment store for $65. We are selling it for $25. Now we have barely used the thing because my son never really took to it. Now there are Childrens Consignment stores that are chains that you might have in your area such as http://onceuponachild.com. Perhaps you have sales in your church. We also have groups that have sales. In our area, we have a group called the Mothers of Multiples. This is all about Mothers who have twins, triplets, etc. They have a huge sale every year. You might want to check in your area for local sales.
Let me mention one other thing about kids that you might not think of. Sometimes we inherit clothes from family members, friends, etc. Anybody that has a boy or girl may know you are adopting and give you some items. Take them, you never know. However, you need to realize that seasons do matter. A child that was born in October vs a child that was born in May may be off in their seasons. You may have 0 to 3 months in Winter clothes instead of Summer. Keep this in mind when planning. Also note that my oldes was born in May and my youngest was born in October. But both kids were premies so now the youngest is able to use at least some of the oldest clothes. You may want to wait a year before throwing out everything to see if there is some overlap.