I suspected the conclusions reached in this thread 8 years ago, but back then there was a lot of emphasis on "puff" clothing, whether down or synthetic. Assuming hiking and not mountaineering (no peak assaults!), these are the conclusions I've reached:
* You generate a lot of heat while hiking.
* It's easier to regulate heat by regulating hiking pace than constantly taking off/putting on clothing.
* Consider whatever you'd wear in the city, just commuting, in similar temperatures and cut it way back. If you are wearing 100 weight fleece, on the trail you'll just need a midweight base layer. Or, considering the heat trapped by the back of a pack, just a silkweight or lighweight long sleeve crew neck.
* The increments on the trail are almost mico in level. It's often not base layer to 100 wt to 200 wt, sometimes its silkweight short sleeve to long sleeve to zip neck long sleeve to midweight/heavy weight in those categories.
* Once you are dialed into the base layer to wear on that particular day at that particular time, an unlined windshirt is the first "upgrade." One with a full length zipper and hood offers the most flexibility, and the Patagonia Houdini seems to the be gold standard (although the Marmot Ion is a lot cheaper). For example, on an early morning hike out of camp, I'll have on a long sleeve silkweight crewneck for my summer/shoulder hikes, and put on the Houdini zipped up. With the hood up for the first part, then hood down, then unzipped, then off comes the Houdini.
* It's not that much different for a winter hike on a trail (no snow shoes), if I am climbing. Except I'll start with glove liners (real simple, light ones) and a mid-weight zip neck.
* Hiking downhill in winter in the shade, I might add a light "watch cap", which is easy to take on and off.
* Most rain evaporates off from body heat.
* Everything changes in camp. Out comes the Patagonia Micro Pull Pullover (don't need the zipper because I don't hike in it). For sleeping, every extra layer goes on. I carry some fleece layers (vests and/or long sleeve) just in case I have to limp out (not much hiking heat) and could get chilled, and it doubles as way to stay warm in camp and select a lighter sleeping bag.
* I'm not a snow-shoe hiker. I hike open trails in the winter at Yosemite elevations, not slogging through snow at Tuolumne elevations. But everything the posters above said makes sense to me.
* Puff jackets are for mountaineers and base camp, not hiking.