Diane Olson, from SAS, wrote a SAS Global Forum paper in 2011 that seems ready-made for this SAS user's Post-It note. Olson wrote about PROC COPY and PROC APPEND. In her paper, she lets you in on the inside tricks on how to clone your data set to the same library, copy your data set using data set options and convert your data set.
Download Olson's paper to take advantage of her cloning tricks. There are other papers on cloning at lexjansen.com; take a look for yourself!