Always be vocal about needing to stop for a minute to catch your breath, sip on water, or grab a snack from your pack for an energy boost. The most important thing you can do is listen to your body, especially as you're climbing to higher and higher altitudes. But you should also be aware of your group's schedule. If you're trying to get to your next tea house (the hostel-like places where people sleep on the trek) before dark, be mindful of not stopping every 20 minutes or taking long breaks. The last thing you want to do is be stuck hiking on rocky or snowy terrain when it's pitch black outside and all you have to guide you is your headlamp!
Image Source: Caitlin Gallagher