Credit: Travel + Leisure Ideal for layering: Amazon Essentials Packable Puffer, $40 Outdoor adventure essential: Nortiv 8 Hiking Boots, $64 (originally $75) For unexpected rain: SaphiRose Rain Poncho, $20 (originally $22) To see wildlife: Amazon Basics 7x25 Compact Binoculars, $22 Lightweight and compact: High Experience Hiking Backpack, $27 An Alaskan cruise had been on my family’s travel wish list for years, so we finally booked one to celebrate my grandma’s birthday with our extended family. The trip was breathtaking, from towering glaciers and misty fjords to wildlife sightings that felt straight out of a nature documentary. But once we started spending hours on deck and heading off on excursions, I quickly realized that there were a few things I wished I’d packed differently. I also noticed the same missteps among other passengers—including my own family members. If you have an Alaska cruise on the calendar, a few thoughtful swaps can make the trip far more comfortable.…