I like it, you have a lot of room for scenery and/or industries. You might add some sidings for industries, mines, etc., if that's where you are leaning.
I'm no operations expert, but: You might also connect part of the yard back to the main and add an aux/caboose spur, as shown in red. If you don't add any industrial sidings, you could do another passing siding near the turntable end, but I wouldn't do both, as it may get too tracky.
Also, if you are so inclined, you could download atlas freeware and draw it out that way, which will help ensure it fits using commercially available turnouts and sectional track. Just guessing your min radius is around 12" now.