Author: Iryna Hnativ, Ukraine
Advice to an imaginary friend from me (someone who has just been on a summer hiking tour to the Lofoten Islands, but generally doesn't go hiking often and doesn't do much sport in principle):
Be ready for rain of varying intensity every day, that's your normal. If the sun suddenly comes out, it's a miracle and a joy.
Take different rain gear, but be ready to get wet anyway.
If you can, take a compact electric shoe dryer.
The most important thing about footwear isn't technology and all kinds of Gore-Tex (everything gets soaked anyway), but a sole with good grip. And good-quality hiking socks. Don't take many clothes — there will always be a chance to do laundry, by hand or in a machine.
The climbs are basically not difficult, but be ready for the trail on some mountains to be laid with high stone steps; on the descents use poles, or knee pads, or something like that to protect your knees. Be ready to scramble on some climbs using your hands (it's nicer to do in thin gloves), be ready to get dirty.
At the top it will be so beautiful it's almost unbearable. But you'll manage :)
Take a swimsuit. If there's a sauna or a jacuzzi anywhere, get in every one. If there's a kayaking option, sign up for that too — you paddle not in the open sea with waves, but among little islands with clear turquoise water. Eat fish and shrimp (they may sell them right off the boat, freshly caught and boiled, and shovel them into a bag for you). You don't need to bring a book :)
Sit by the water in the evening with a cup of tea. Wait for the polar sunset, you'll catch up on sleep at home. Don't miss anything at all — you never know where a double rainbow will catch you. Take a hat, listen to the team leader's advice. Eat blueberries straight from the bush.