How to make separated bed frames?

Hey! I take this to mean you want to do your own separation without using someone else's separations as a base (as this tutorial does). I just did this with the Cordelia Bed, so I can tell you how I did that, but I can't promise you won't run into any issues doing a different bed since it's my only bed separation so far.

Also, note that annachibi's separated frames can be used as bases for recolors/edits, and brazenlotus's CC can be used for recolors without the meshes included, so if you were wanting to separate one of these, you don't have to redo all that work.

But if you do want to separate some beds, here's a sort of TL;DR of what you want to do:

1. In S4S, make sure you select Create 3D Mesh to start.
2. In the Studio tab, go to Meshes, and export all the meshes for the bed. Use descriptive filenames so you can keep them all straight—like Bed0, Bed1, Shadow0, Shadow1, etc. (When editing meshes, I usually just keep this package as a base to work from in case I need to pull the base meshes again. When I'm ready to make my new item, I create a new package and leave this one alone.)
3. You'll need to edit each of the meshes in Blender twice, basically: once to get the mattress separated, and once to get the frame separated. Make sure that, when you save your edited meshes, you give them new filenames instead of saving over the original ones, so you don't have to re-export the base meshes again. I usually name mine things like Frame0, Frame1, FrameShadow0, FrameShadow1, etc.
4. When you're making the mattress-only meshes, make sure you hide the bed frame in the mattress. Don't just delete the whole mesh group the frame is on. All you need is one triangle of points, and then you can make it tiny and move it so it's inside the mattress and can't be seen. (See also: this thread.) I don't know if you're supposed to do the same with the frame-only (hide the mattress in it) but I did not and it seems to have worked fine, so bear that in mind.
5. Once you have all your separated mattress and frame meshes, do Create 3D Mesh two more times to create two separate packages: one will be for your separated mattress, and one will be for your separated frame.
6. For the frame package, upload your new frame-only meshes in place of the default ones. Make sure you upload the right ones in the right spots (this is why naming them understandable things is important).
7. Remove the footprint for the mattress.
8. Change the prices! Your separated pieces will have the same price as the full bed by default. I split mine so that 2/3 of the price was the mattress and 1/3 was the frame, because that seemed to be what other creators generally do.
9. Test in-game. You might still need bb.moveobjects on to place the separated mattresses on the frames.