Hi Arlene: Reason for asking about dates is your comment about what to pack. Best advice given by Untourists is to layer, layer, layer. Our preferred dates are mid-May to mid-June so we get another spring in Sachseln. On my do not bring to CH (short for Switzerland--Confederation Helvetica) is heavy sweat shirt, heavy sweaters, heavy hiking boots, heavy jeans. Hiking boots have evolved into wonderful light weight shoes (and waterproof to some degree). Reason for all those "no heavies" is they do not layer well. Everything lightweight. I do include a light weight sweatshirt and one light sweater. I bring cotton or cotton/poly shirts which can be rinsed out and dry overnight, Land's End/Appleseed light T's are good, they launder by hand. I have lightweight cotton corduroy pants with elastic waistbands (the better to eat CH sweets) an coupes (ice cream sundaes). Good for hiking and light to pack. CH is casual. No jackets required for men. OK to be casual at the Untours party. Must mention that we have visited during several European hot spells. I pack shorts and 2 light cotton blouses just in case.
The local Sachseln market has everything you will need. The metzgerei (meat market) very close to you has terrific meat. And we (Sachseln) has outstanding pastries at Cafe Zum Stein. A good place to have a light meal. Several excellent restaurants, and the reliable Bahnhof restaurant has good meals, including the good CH gemischter (fresh veggies, lettuce) salads. Potato salad is a veggie in CH!!!! In the next town towards Lucerne, Sarnen, you will find more shops, a Migros, a Coop (the nat'l food chains), more restaurants, cheese shop, bakerei(s), etc.
You asked about gifts. Your idea of a Hallmark gift is very nice--perhaps picture cards without an English message? Something from your local area is always thoughtful.
Did I mention rain gear which is a must. Again, large enough you can add warmth beneath. You will be going "upstairs" to the beautiful high mountains. It is cold in the higher regions, even in the summer.
Weather varies from year to year. We have been 12 times to Sachseln and the weather pattern has been different each visit.
My personal preference for walks/hikes is no back pack. They get heavy and tiring. I am able to use a ruck sack and get most everything I need in that I need, including a string bag (or two) for shopping on our way back home in the evening.
Hopefully this gives you a idea or two. Perhaps some specific questions. Happy travels with the best travel folks in the US! Joan