Take a deep breath! Sorting is not as hard as it may sound. You may hear 'sort' tossed around the sale by veterans like it is a dirty word, but on this scale, it's a piece of cake! It also is going to make entering your items a whole lot easier.
Now that everything is fresh and clean and you have a good idea of what you will be consigning, sort it.
I know, I know... but how?! That's up to you! My system? Keep on scrolling.
Sort by Gender
Sort by Size
Sets need to be the same size and same brand. Someone probably will not buy one body suit for $2.00, but they may buy a body suit and pants for $2.50! Sets help you sell more and are more convenient for our shoppers. Think about how you shop; would you rather buy a little outfit or single pieces? It can be a little from column A and a little from column B, but for infant sizes (Newborn - 24m) sets sell better.
Ta-da! Now you should have several groups of clothes ready to go. The next step you take will be preference. For me, I prefer to prep, sort, hang, enter then tag. Hanging items is what takes me the longest. I find that once I have my piles or baskets, I prefer to hang by size, enter that size, set it aside and repeat. That is just what works for me. You will have to give it a go to see what works best for your flow-jo.
Obviously the above focuses on clothes, but you can use the same guidelines for toys, books, shoes, etc. Sorting your items in to smaller groups makes the process a little less daunting and you are less likely to get overwhelmed, especially if it is your first time.