Over the years, I've tried everything I can think of to lower the packing weight of the stuff I carry. Right now, I'm down to 35-45lbs. Is there a way to get lighter? (short of not shaving or not packing any soap, I'm unsure of where to cut next.
Are you trying to lighten the load for the sake of lightening the load? If I can comfortably carry X I am not going to bother trying to get X-1 just because I can or because it might make things easier.
In any event, one approach is to not look to ditch any particular items but rather examine whether there are lighter alternatives. Off-bike shoes is one place to start. Crossing the country I took a very lightweight pair of slip-on "bo-bos" from Woolworth's. They were noticeably lighter than the sandals I have taken on my last tours. Years back I read an article that mentioned how some people will cut off the ends of their eating utensils and toothbrushes to save a few ounces yet pack denim jeans that weigh substantially more than synthetic pants with zip-off legs. Towels can also vary greatly in weight, even at comparable sizes. Since I don't want to replicate all the comforts of home when I tour I take a pretty small, thin towel to save space and weight.
You mention shaving. If you carry shaving cream, do you have a full-sized can or one of those travel sizes? Soap. Do you carry bar soap and something to wash cooking gear? If so, one bottle of Camp Suds or Dr. Bonner's will work for both and can also be used as shampoo.