I checked the help wiki but it doesn't tell how to organize lots in LotCatalog. I found another site that says to renumber the files using Clean Installer. Is there an easier way? Also, can I put subfolders in the LotCatalog folder?
Thanks!

I just make a hood called "House Holding Hood" and place all of the houses in the bin there and then delete them from the bin and now the only ones in the bin are the ones I just put there to place in other hoods.

After installing the houses in a hood I delete the copy in the bin because I still have a copy in the "House Holding Hood".

After placing the house in the bin make sure to place a copy back in the "House Holding Hood" for safe keeping.

I guess that would work. Thanks for the tip!

/edit
I may need more than 1 hood. Didn't realize how many lots I had. I will need a Moo Village, a Plastic Town, and a Larsson Acres for sure.

I don't know if there is an easy way to go about this. I spent a whole weekend not long ago sorting my lot catalog (I currently have 474 lot files in there and I still need to do more sorting with some of them). After backing up my whole LotCatalog folder, I decided on ranges of numbers for each category (500 - 600 for University dorms, 600 - 700 for NL nightclubs, etc. - have a notepad file open or something so you can keep track of this). You may have different categories that you want to use.

I took all the lots out of the catalog and put back a few at a time (5 or so) to see what they were, renumbered them (and wrote in Notepad which lots were assigned which numbers), and pulled them back out into categorized folders. Once I had them all sorted, I put all the files back in the game's LotCatalog folder. Do be aware that this process is further complicated by the fact that some lots will not show up in some locations (dorms will only show up if you're in a University campus, apartments will only show up if you're not in a University campus). I also kept a copy of the notepad file in the LotCatalog folder with all the info on it about which lots were which numbers and named it directory.txt. File numbers for the lots MUST follow the existing format: cx_00000001.package. You can use any numbers you want for your lots, but the numbers MUST be exactly 8 digits long.

I hope I'm making sense trying to explain this to you. I confused myself a couple of times in the process of writing this post. Just remember - back everything up and write everything down!

I've been mad at Maxis about this for years. Each time a new EP was released I hoped that they would bother to add at least a few simple sort filters to the lot catalog, but they never did.

I used Marka93's method and made a House Town hood with 2 shopping districts. That way I can actually examine a house and make any changes before I plop it in my hood. I did weed a few out. I had some 4x4 lots that cost 300k+. I would never play those but boy they are beautiful. I also had a few duplicates or near duplicates.
Main hood has residential lots I've downloaded, 1 shopping district was all the commercial lots I've downloaded, other shopping district was all the Maxis lots, which I never use.
Thanks for the help!