Hikers should be prepared for weather changes and carry with them raingear, hats, gloves, and jackets, as appropriate. Sturdy footwear is essential. Each hiker should also carry the 10+ essentials:
Washington Trails Association's "Ten Essentials" web page is here.
The Mountaineers Hiking Basics brochure is here.
The club strongly recommends, but doesn't require, two way radios as we often spread out while hiking at different speeds and the radios allow us to communicate with others who are out of sight. They make the job of the hike leader much easier and can be indispensable if someone gets lost. If you want some help in choosing a radio, read this.