I agree with KevinL's comments.  In recent years, I have used the very same shelter solutions... hanging (when alone or in an odd-numbered group) & a CCS Lean 3 shelter for a larger party. 

My answer to the "insulation" challenge has been my Clark Jungle Hammock (see: (You need to Login or Register to view media files and links) ).  It's pricey but I have gotten more than my money's worth with various iterations of this product over the years.  Among its many fine features are the six huge pockets on the underside.  I fill these pockets with my wool socks & other clothing.  Even when I woke up in a nasty snow squall last May I was quite warm and comfortable... as long as I remained in my hammock!

Other hammock models have their advantages, too, but, during cool nights in the summer and the "shoulder seasons", I find that the Clark Jungle Hammock solution (stuffing the underside pockets with my extra clothing) works plenty well and I don't have to carry any extra insulating blankets. On REALLY cold nights I have gone the additional step of stuffing my life preserver underneath my sleeping bag AND hopping into a CoolMax liner (adds an additional 10 degrees) while inside my 20 degree sleeping bag.

Positioning the hammock in an area that is well-protected from the likely night-time wind direction can also save you from substantial thermal loss.

Re: "angles" & "spacing", my words-to-the-wise are: watch those videos that KevinL mentions AND practice, practice, practice.  I've strung my hammocks for years, now, and I'm STILL practicing.  When the angle isn't right, it can be a frustrating experience; you can't always find trees exactly where you want them.  "Skill" eventually grows as you play around with your hammock in varying environments and conditions.  It's seldom the same set-up twice.

Anyhow, when done right, it can be some of the most comfortable sleep you will ever experience in the wilderness.

Jimbo