I started the journey to ultralight 5 years ago and have gotten down to sub 8 for all three season trips, sub 6 for long weekends, and sub 5 for light and fast overnights.
One thing I found is that I frequently slept cold and didn't carry enough insulation. I started with a 30 degree bag and switched to a 30 degree quilt, then started going to lighter and lighter quilts.
Daytime naps in the sun are a great way to recharge, but I found that I prefer to take a small weight penalty and carry more insulation.
My current setup is a GoLite Ultra 20 quilt and a Micropuff pullover, with a lightweight pair of poly long johns and two hats, one is a lightweight dense weave beenie type hat and the second hat is a fleece bomber hat from Mountain Hardware. The beenie can be worn while hiking and sleeping, then if my feet get cold at night I slip on the bomber hat and cinch it down.
Also ..... I clean up before bed and put on a fresh pair of dry or dried and freshly laundered socks to sleep in and wear the next day. Don't sleep in your hiking clothes, but slip into your dry and clean lightweight long johns to sleep in. You'll be surprised what a difference this will make in your quality of sleep.
Next .... if your pushing the temp limits of your quilt, then pitch your tarp low. I pitch mine in a half pyramid and then wrap my poncho around the front, leaving a small air gap at the top. This will trap heat and add 10 degrees to your sleep.
If your going to cowboy camp, and aren't going to pitch a tarp, then find a spot with some good tree cover ... It's always warmer under the trees, a bit off the valley floor, and on the lee side of a hill or rise to block the wind.
It's easier than you think.
A good ground cloth is critical to blocking moisture (humidity) from infltrating from the bottom. Even using a Bivy I've found that I sleep warmer with a 1.7 oz polycrow groundcloth under me.
Lastly is the pad .... I use a 15 oz. 3/4 length primaloft inflatable pad ... my old back insists on it. But when the temps are pushing freezing, I'll add a 1/8 inch thinlight pad under it. Big difference!
You are the only one that can determine what you are willing to sacrifice when you're hiking .... you can go extream and hike at night and sleep during the day, or you can go for max comfort. The scale in between is almost infinite ..... myself, I'm willing to pack an extra lb and a half for anything longer than one night to insure a good nights sleep.
Last point .... dramamine is the best sleep aid I've found .... two dramamine and I can sleep on a oak board for a full night .... although I won't hike too far the next day with sore hips.