Really hot > 100F:
Rail Riders Eco-mesh shirt and pants, Ex-officio boxer shorts. Tilley LT4 hat. Light poly low top socks. The lightest running shoes I can find.
Accessories/other: Ex UL Jacket or vest (sometimes hike from desert to alpine), Houdini Wind Shirt, Poncho, glove liners if at high altitude.
Not so hot/So Cal Shoulder:
Very light running shorts, no liner, no briefs. Light merino/poly long sleeve shirt. Usually no hat. Light poly or merino or blend low top socks. The lightest running shoes I can find.
Accessories/other: Same as above except maybe a eVent baseball cap if it is going to rain a lot.
Capilene 2 top, Some sort of Schoeller pants, often an eVent hat with ear flaps, lined with primaloft. Sock liners, Rocky GoreTex Socks, Mid weight wool socks. Size up on shoes (Salomon XA comps breathable). OR Verglas Gaiters.
Accessories: R1 Hoodie, Houdini Windshirt, Capilene 2 bottoms (sometimes hike in them alone with UL running shorts), poncho, sometimes WPB jacket, sometimes rain skirt, Ex UL down midlayer, NB Fugu, Mount Bell down innder pants, 2 or 3 pair glove liners, eVent Mitts, sometimes insulated gloves, some sort of beanie/bacalava may be more than one, extra wool socks.
Every trip is different so I often mix and match. Sometimes in heavy cactus country I will wear Salomon XA comps breathable. Sometimes in cooler weather with gastly amounts of sand I will wear GTX Salomon XA comps to keep the sand and dirt out. Once in a while dirty girl gaiters or eVent shorty gaiters... usually only once or twice a year.
Once in a while I will hike in some sort of long sleeve nylon shirt and/or pants because my wife did the laundry and I cannot figure where she hid/placed the Rail Rider stuff even though I have 4 sets of each. I have many Columbia, REI, Ex-officio shirts and pants (they are an easy Xmas gift for someone who doesn't want gifts). But usually use the Rail Rider Eco-mesh. Never, ever use convertible pants because I just hate them. Because I get to hike a lot, almost every weekend there are smelly clothes in the hamper and my wife won't wash them unless they start to stink up the house. Plus she isn't going to do a special wash for Merino, and I once caught her trying to throw 3 down jackets and a pair down pants into the washer... luckily I caught her just in time :)