Over the years I have found that the bulky items and overpacking are the biggest culprits. Two years ago Bobby and I had a two night trip to Crag Camp in which at the end of the trip we realized that we each had food bags that weighed in around 10 pounds and we had not even eaten half of that...
I used to carry way too many clothes - I have been able to cut way back on that...
Beyond that, I find that over time I have replaced older gear with newer, lighter items - some examples...
Old camping Gaz stove ( a few pounds with fuel) has been replaced by homemade Cat alcohol stove (a couple of ounces with base and windscreen)
Old 20 degree sleeping bag (over 4 1/2 pounds) replaced with 15 degree Marmot that checks in at 1 lb. 10 oz.
EMS 4700 cu pack is around 7 pounds empty - Go Light 5500 cu pack is about 3 1/2 lbs. empty.
Old MSR water filter was about 1 1/2 pounds, new MSR Hyperflow is about 7 ounces...
My cookpot went from about 10 oz to about 5 oz...
My current tent is an EMS Starlight - about 5 lbs...next time I need a tent I am replacing it with a Shire Tarp tent with bottom - about 2 lbs...
Old polyester longjohn bottoms were almost 1 lb - new silk ones are a couple of ounces - and they seem warmer...
I have stuck with thermarest pads and have stayed away from th self-inflating types that weigh a lot more...
Food - figure what you will need and then bring maybe one extra meal and a few extra snacks...remember - this is the Whites - not backcountry Alaska - how far will you be from your car or civilization if you run out of food and need to get more?
Nalgenes - I like them for filtering and measuring, but they weigh 7-8 ounces empty - my solution is to carry one and a Camelback...gives me 4 liters of capacity and not too much weight...empty Gatorade jugs (32 oz) are a good size and toughness and weight a lot less...
Multitools and knives can weigh a lot - as can some headlamps that are older and use heavier battery types...
It is a game - getting the packweight down...and not going broke in the process - but, the enjoyment you get when you are only carrying 30 lbs, and not 50 is immeasurable!
Good luck!