+ 1 Life is a lot easier once you ditch your cottons and wear a baselayer top (and bottoms if needed) + base layer boxers. I only take socks with me now, it's a little dirtier, but a lot lighter.
I only started to lighten my load about a year ago. First thing I did was ditch every unnecessary item, remove all spare items (i.e. just headtorch, no backup torch) and lighten up the cheap stuff.
I also cut down by finding smaller bottles for contact lens solution and taking a simple waterbottle instead of a bladder.
Once that was done, I bought a decent down bag that is relatively light for it's comfort rating (alpkit pipedream 600), a new light-ish rucksack (Osprey Atmos) and a new tent (Wild Country Zephyros 1).
Now obviously those were fairly expensive bits of kit, but a significant amount of my weight was lost just by leaving stuff at home. If you don't have money to spend, don't worry, just cut what you can.
+1 again, I bought the Gelert Solo first as a cheap lightweight tent. I tried it out on a 3 day ridgeway hike and it was a little small for me. Fine for sleeping in, but you can't sit up in it to get changed, and the major problem is that you can't cook in it. This was OK for me as it was summer, but I knew it would be a problem in the rain. I ditched it and spent a bit more money on the zephyros instead. It's a great tent.
