Got some proofs in the mail today. I haven't gone through them, but I'm just happy that the covers turned out, because I got error messages on both of them.
Why did I also include photos of unrelated TPBs? To show that the size I chose, 8 x 5.25" is the closest to actual TPB size. I wish Createspace offered 8.25 x 5.25 or 5.5, but they don't, and 8.5 is too tall. 8 x 5.25" is the only standard TPB size they offer (both of the above books are that size). A lot of people go with 9 x 6". That's hardcover size, so it looks weird unless it's like 700 pages. And why would you want your page count to be low? To make more money off paper sales? How many paper books do you sell versus e sales lost due to low page count? The only reason I made these is so that Amazon will replace their too-low estimate of Psychomancer and Blood Tells True, which I know is hurting my sales.
Everyone has their reasons, but 8 x 5.25" makes sense to me.
From what I heard, if you don't use Createspace (meaning if you go with Lightning Source), your page count doesn't get corrected. I don't know if that's true or not.
PS I got these after reading Helen Hanson's post, which explains how Createspace has repeatedly messed up the cover of her most recent effort, due to what I believe is the same error message I got. I got lucky.