Assuming you already have folders, just select a parent folder (on my Mac it's /Pictures) and right click, select "Create folder inside "Pictures"..." and off you go.
Or when you import you can have LR default to creating date named folders, and so any new 2015 photos would automatically go there.
Thank you, but based on your answer I now realize that I should have asked how to set up a 2015 "parent folder." I already have separate folders for 2008 thru 2014. Each of them has dated/named sub-folders representing each time I go out on a photo-shoot. Now I want to set up a 2015 folder for each shoot in the new year. Help.
It's the same process. Once you put other folders into it the 2015 becomes a parent.
Again, use a right-click on the parent folder of 2008, 2009, etc. Make it "2015." Then right click on "2015" and make a folder inside, like "January" or whatever you want. If you don't see the parent of "2008," use "show parent folder" by right clicking on 2008 to display it, then do as I said. If you have
If you import from a card, you could also use "Organize" "by date" in Destination in the import module with a date format like "2015/2015-01-23" and it will create that folder.
If you are storing on an external drive, and the year folders are at the root of that volume, that may present some issues. Generally I find it preferable, at least on my Mac, to have them all in one parent folder and NOT at root level. On the Mac I'd just do that in the Finder, but I don't know what OS you're using. You can get that root folder in by placing one image in it and importing it, then you can chuck the image.
If you are talking about doing this in the import module, right-click on the folder that you want to be the parent folder. You can add your 2015 folder right there. Then make sure the 2015 folder is highlighted. Above choose "into one folder" and also check into subfolder. Then you can name the subfolder such as January, for instance.
Thanks for your additional input. I finally got it - success! I have two external drives (LR Library and LR Backup Library) and I'm working on a Macbook Pro with OS X Yosemite, Version 10.10.1.
Thanks for your help. Mission accomplished!