Store-->Designer-->Retired or Current-->Kit Name
With the exception of, I usually shop on Saturdays, and end up with more kits than I can use all at once, so I unzip everything I get on Saturdays into a folder with the kit name, and they stay in the folder called "Unused Products" until I've used them. Once I've used an alpha at least twice, and a kit at least once, it goes into my standard organization. For things like the sweet shoppe quarterly or other assortments that are bundled minis, I have to use at least 3 minis before I move it over... it just is my way of ensuring that I use what I buy.
So often when I first started scrapping, I'd buy any kit that looked even somewhat cute, and then found out that 80% of them, I ended up putting in folders and never even unzipping! So now, I do this added step of "unused products" to make sure that I use everything I buy at least a little bit.
For the designers I CT for, I also copy/paste all of their kits into a folder specifically for my CT work, and I put a layouts folder in there, so I can place copies of all my layout previews that I upload in this one folder... it makes it so much easier!