Our single best piece of advice when planning a trek is to build a couple of extra days into your itinerary and include some of the following side trips. The scenery is more spectacular, the trails are wilder, and the crowds are noticeably thinner. If you're lucky, you might even have the following gems to yourself.
Langtang Valley Trek: Extra Time in Kyangjin Gompa
Many people choose the Langtang trek because it gets you into the heart of the mountains in just three or four days. The key is to give yourself enough time to savor the real highlight of the trek: the peaks and valleys around the village of Kyangjin Gompa.
Most people budget one day at Kyangjin Gompa to climb to the popular viewpoint at Kyangjin Ri, before turning around and heading back down the valley. In fact, you could easily fill two (or even three) days in this remarkable area. The demanding full-day hike to the viewpoint atop Tsergo Ri offers an even more spectacular panorama than Kyangjin Ri. There's also the full day or overnight hike to the Upper Langtang Valley, where you'll find alpine pastures and meadows around Langshisha Kharka. A shorter half-day excursion takes you along the glacial moraine flowing off Langtang Lirung peak, providing up-close views of the Kimshung Glacier.
For something a bit less strenuous, walk an hour to the Tsona Lakes, where the chain of five forested alpine tarns and flower-strewn meadows are the perfect places to kick back with a picnic and take in the birdsong. It's even possible to continue uphill from here for a couple of hours to Nyengang Kharkha for awesome views of the Upper Langtang Valley.
Adventurers can even hire a tent and guide in Kyangjin Gompa for the exciting two- or three-day ascent of Yala Peak, an 18,000-foot (5500 m) summit that requires good fitness and acclimatization but no technical skills or permits. It's as exciting a trip as you'll find anywhere in Nepal.
Chat with a local specialist who can help organize your trip.
Gosainkunda Trek: Explore Hidden Lakes
If you can add just one half-day excursion onto a Gosainkunda itinerary, make it the half-day walk off trail to the half-dozen or so alpine lakes that lie hidden in the tundra-like landscape above Gosainkund Lake. Head for Dudh Kund (Milk Lake), Chandra Kund (Moon Lake), Ragat Kund (Blood Lake) and Ama Kund (Mother Lake), and that's not enough there are even more lakes to explore just below the nearby Laurebina La pass. It's also possible to hire a local guide and make the adventurous scramble up to Surya Peak, though this is a much tougher prospect for those with a good head for heights.
Everest Base Camp Trek: Venture Off the Main Trail
The scenic highpoint is the Gokyo Valley, where the viewpoint at Gokyo Ri offers stunning views over the valley's huge glacier and chain of impossibly scenic turquoise lakes. A less well-known trip for fit hikers is the long day hike to the icy alpine lakes at the base of massive Cho Oyu, the world's sixth highest peak. You'll need at least four days for a return trip to Gokyo from the Everest Base Camp trail, either on the way back down from Everest Base Camp or, even better, via the high crossing of the Cho La pass.
Good acclimatization is essential if you are headed to Everest Base Camp and one great way to help with that is to spend an extra night in Namche Bazaar and make a loop day hike up to the Sherpa communities of Khunde and Khumjung. Both villages boast stunning views of Ama Dablam, perhaps the region's most beautiful peak, and you can detour up to even better views at the Hillary Memorial Viewpoint, where three stupas commemorate Ed Hillary's wife and daughter, who both died in a plane crash nearby.
Annapurna Circuit Trek: Better Ways To and From Manang
The trails around Annapurna are busy in high season and road construction continues to eat away at both ends of the Annapurna Circuit trek, so the alternative trails and detours here are even more important than elsewhere. The best way to avoid the main road to Manang is to take the alternative high trail from Pisang via Ngawal. Not only does the detour help with acclimatization but an overnight in the charming stone village offers epic views of the Annapurna range.
There are also several good acclimatization day hikes from Manang. From the beautiful, traditional village of Bragha (itself well worth a detour) you can hike for a couple of hours up to Milarepa's Cave, an important Buddhist pilgrimage site that is almost hidden in a mass of prayer flags.
From Muktinath on the west side of the circuit there are two adventurous detours to consider; one half-day hike to the photogenic traditional Mustang-style villages of Jhong and Purang; and another down past the interesting Bon monastery at Lubra, to rejoin the Annapurna Circuit further down the valley. Both hikes avoid the paved road and its jeeps.
Manaslu Circuit Trek: Pungyen Glacier or Pungkar Tal Lake
There are several excellent side trips to be made from this increasingly popular Manaslu Circuit trek. Our favorite is the Pungyen Glacier detour from Sama, a half-day hike which offers fabulous views of 25,820-foot (7870 m) Ngadi Chuli and 26,760-foot (8156 m) Manaslu peaks.
The other great side trip to consider is on the other side of the Larke La pass, where a side trail from Bimthang leads to beautiful Pungkar Tal lake with its dramatic views of the wall-like Cheo Himal range.