Markha Valley
I did the the Markha valley trek in 3 days starting from Zingchen village, where are taxi dropped me for 1,500 Rupees from Leh market. I ran up to Yurutse, Ganda La pass, Shingo village and down to Skyu were I stayed for the first night.
On the second day I crossed the entire valley to Hankar via Markha village.
On the third morning, I hiked up to Nimaling for a cup of tea and crossed the Kongmaru La Pass, ran down to Chogdo and finished at 2pm. A taxi picked me for 2,500 rupees (maximum price from there is 3k). On top of Kongmaru La pass you will have network, make sure to call you driver from there. You might be able to find other people to share a taxi with.
This is a very popular trekking route and normally takes up to 8 days. When I was there, there was heavy rain the days before in Ladakh, so I found some snow at Ganda La pass but no problem. Going down do Skiu, I had to cross the river many times, the water was a bit rough and the gorge had some rockfall, so be very careful there. With normal weather, it should be very easy as its a highly frequented route. The Markha valley section itself is smooth.
Going down from Kongmaru La the river was rough again, but the water was more clear here. I stayed in homestays for both nights which costs 1,500 rupees per night and I found it very comfortable. I think homestays are ideal for fast-packing and ultra running.
Overall it was an incredible experience. I want to come back and run this route in one day as an ultra challenge.