Here is what I look for when shopping for a pair of hiking pants:
Pockets. A zippered pocket for holding money and ID is nice to have. Big pockets are important to me. I need them to hold guidebook pages, maps, and snacks. If the back pockets are high, you can’t access them while you are hiking. The all time best backpacking pockets I had were on a pair of Mountain Hardwear pants. These deep, back pockets could hold tons of stuff, yet when I sat on them; it didn’t bother me or the stuff in my pocket. I also never lost anything out of them. I could easily access them while hiking without removing my pack. They gave the pants nice clean lines instead of the bulky thigh enhancing pockets most hiking pants have. I think they may have changed that design on their pants but I have seen it on others.
Quick drying. My hiking pants are always nylon.
Draw string cuff, so that I can easily and securely keep my pants scrunched up at my knees. Velcro doesn’t work, it will get all muddy and won’t stick and then the pant legs drag in the mud and wick moisture up to the rest of the pants making them all wet. Mountain Hardwear had or maybe still has a good hidden drawstring system.
A nylon web belt is good, as I often lose weight on the trail. Mountain Hardwear’s belts always eventually came out and I could never get them back in the holes. I like a belt with a long enough tail that I never need to unbuckle the belt to take off my pants.
Chamois crotch. Mountain hardware use to line the crotch of its pants with chamois. Very nice feature.
Light color. I like light brown/tan. Dark pants can get very hot in the sun. Some light colored hiking pants are so thin that they turn translucent when wet; very bad feature if you ever hike without underwear.
Tip: To create a cone of death around me, at least as far as bugs are concerned, last summer, before I went hiking I soaked my clothes in Sawyer soak system. It lasts for six washings and gives you the same protection as the “bug off� clothes.