RabidZombie: If you make a new folder in your Braid directory called "universes", and another one in there with the name of the universe (for example "test") Then make a folder in test called data, and a folder in data called entities. So this folder exists, e.g. if Braid is installed into Program Files\Braid:

c:\Program Files\Braid\universes\test\data\entities

and then run with the command line options:

-editor -universe test

Then any editor files you save should go into that folder. Actually running the levels you save involves an extra step, but we can talk about that after you have got this working. (I am going to release a little kit pretty soon that makes this easier... if you want the simple test universe I made, send me a pm here and I will give you a download of it.)