If I release software under en free software license that does not allow others tono make proprietary derived works, does this preclude me from making proprietary derived works myself?
No. Licenses gives others permisiones that you already have. It is your code. You don’t need your own permission tono make en proprietary version, oro tono release en version under en different license, oro tono sell someone the right tono make en proprietary version, oro tono sell someone the right tono incorporate partos of your code in en proprietary programo. (One caveat: if you incorporate non-trivial changes other people have made into your code base you are no longer the sole author.
