One of the best things I ever did was lighten my bag in the Berg. This came about through necessity when climbing in winter. The additional weight of climbing gear + water meant that you couldn't have more than 12kg of other (non climbing) gear and still enjoy things - climbing gear came in around 10kg with climbing boots, harness, rack, ropes etc.
The essential change to mountain gear in the last 10 years has been a significant reduction in weight. I find that climbers with heavy bags tend to take too much clothing. I just take 2 long sleeve shirts (one of which I wear), two pairs of running shorts (one of which I wear) and a pair of lightweight running longs. A single fleece and lightweight raincoat are good for summer. Its never really too cold when you're hiking and if you're cold when you stop, then the sleeping bag should do the trick. The Berg is blessed with caves in 2 types of rock which is hugely unusual in the world. So I very, very seldom pack a tent. Bivvy bag yes.
After this, the most critical factor is fitness - so that if things go wrong, all or one can get out quickly. Anyone find any of this stuff on sale anywhere - give me a shout!
There are a few tricks with food as well. One I use regularly now is to take a minimal load of sugar and use those awful tasting diet sugar pills. These add the sweet taste and just a little sugar disguises the taste of the pills.
If you think you carry too much stuff, check out what is in your bag when you've finished a trip that you either didn't use or didn't really need. Not all of this can be left behind next time - but at least some can.