I think I would ditch the spare underware and always take a fleece hat - the weight is about the same. Never understood the need for spare underware-I simply go without when I wash my underware. My husband goes totally "natural", thus saving the weight of underware altogether!

Just think of double duty for every item. Since I usually take a dip at the end of each hiking day, and wash my hiking shirt anyway, I simply dip first, and then use the shirt for a towel before I rinse it off.

Think hard- do I really need that? I used to alawys carry a compass. After years of never needing it I simply quite taking it. GPS? - no I just do maps. Maps? - if I am really familar with the area I go without. Headlamp? Leave it home mid summer when there is more daylight than I can effectively use anyway and do not take it when there is a full moon. TP- I have cut this in half by using a "pee rag" (mine is a baby washcloth). Frying pan? Unless I am cooking fish every night I just fry fish in my 1-qt titanium pot. Electronics?- just say no. Group gear? If going with a group or someone else, bring one stove, share what you can in emergency gear. Down sweater? A luxury item (not a 100% insulating layer because if it gets wet is is worthless). Sometimes do not take it and simply hop into my sleeping bag early if it is cold. "Extra" anything? just be careful not to lose anything and only take gear that is in good shape to begin with.

I limit non-essential stuff to one pound. Sometimes that means taking fishing gear, but not the down sweater; or the thicker sleeping pad instead of fishing gear; or camp shoes instead of a book.