I got this from SW, although if I could have done it the other way it would have been better. A bit more time and I could have used actual modeled copper or PVC pipe. Anyway, you get the gist.
It's more about even coverage with batch sparging than anything. Although, if you even think you will want to do fly sparging in the future, and don't want to build a manifold twice, consider making one that will be efficient for fly sparging now.
I'd probably add a crosspiece to each end, but the method I used to draw this up wouldn't easily allow for that to be added.
You could forego the piece across the top and bottom of each square, as suggested, and add another vertical to each each one, but you'd have to find some crosses, and caps, instead of more corners and Ts...