Formal attire: For obvious reasons, this will not only be uncomfortable, but the items could get ruined on the overnight. You’re not headed to a gala, so save those ensembles for another night.
Jeans: The jean material doesn’t allow for the flexibility and breathability you’ll want on your hike. Choose lightweight cotton items or quick-dry items instead of heavy jean material.
strong Bulky clothing: You’ll want ease of movement, so don’t let anything get in the way of that! Dress in layers, and don’t over pack.
Non-breathable fabric: From head to toe, you’re likely to work up a sweat while hiking. Quick-dry fabrics will be your best friend. Consider your footwear choices, too—some shoes have a more breathable design than others. This one by Flarut is an example of a breathable hiking boot, if your hike is mild to moderate.
Uncomfortable shoes: A few days before your hike, wear your shoes for a day or two to see how they feel. You won’t want to find out 3 hours into your hike, that they rub your foot the wrong way. You can bring along a couple pieces of moleskin just in case.
Jewelry: Anything that hangs off your body could get tangled up as you traverse the wilderness. Not only that, but it’s (although slight) extra weight that is unnecessary. You wouldn’t want to lose an earring or bracelet either; even retracing your steps, it would be nearly impossible to locate a small lost item. Focus on nature, breathe in the fresh air, and worry about jewelry when you return home.