What should I take for trekking?

There is no definitive answer. This is a suggested list, perhaps the minimum necessary. You should adapt it to your own needs and the requirements of your trek. Ask yourself: Will there be snow / how long will the trek be / how high will I trek/will we be camping?
  • 1 light sleeping bag 1) [some lodges provide blankets]
  • 1 T-shirt, not a vest or singlet [preferably fast-drying]
  • 1 thin fleece or a 2nd T-shirt
  • 1 long-sleeved shirt
  • 1 fleece jacket
  • 1 light waterproof/ windproof jacket
  • 1 pair of long trousers (women may consider trekking in a long skirt – NO SHORTS)
  • 1 pair of walking boots or sturdy trainers
  • 1 pair of flip-flops/chappels/thongs
  • 3 pairs of socks
  • woolly hat, scarf, and gloves
  • 1 first aid kit [medicines are not easy to get on the trail]
  • water bottle and iodine tablets
  • torch [flashlight], with spare batteries and bulbs
  • penknife [preferably with scissors]
  • map and compass
  • guidebook, phrasebook
  • camera and films [spare battery if it uses one]
  • pencil and small notebook
  • minimal wash kit including biodegradable soap, toothbrush and toothpaste
  • bag for carrying out rubbish
  • extra plastic bags – they weigh nothing and have many uses
  • sanitary items for women
  • sunglasses, sun hat
  • lip balm and high protection sunscreen
    •

pleasant extras:
  • a book to read
  • photos of home and family are good for breaking the ice
    •

Consider a down jacket and windproof trousers if trekking over 4,000m.

Note 1 Sleeping bag: A good night's sleep is essential for enjoyable trekking. When trekking at altitude or between October and mid-May, a good quality [down?] 3–5 season sleeping bag is recommended. It has been known to snow in October in the hills.

… And don’t forget a smile and a sense of humor!