Using CD-RW media Mini Howto FAQ

CD-RW drives usually support packet writing, but as there
is currently no usable UDF filesystem support you may only use
the simple cdrecord approach.

Cdrecord writes to CD-RW media in exactly the same way as it
does with CD-R.

You may erase a complete disk in preparation to reuse it.
Check the man page entry for the blank= option of cdrecord.
Not all drives support all blanking modes. Usually
blank=fast or blank=full are working.