Fail: Not enough water
One thing to remember when cooking at high altitudes, is that water will evaporate faster compared to sea level. Once, I left a pot of noodles to boil over the fire and got sidetracked doing other things. What I found when I came back was a bunch of burnt noodles sticking to the bottom of a pot with no water.
If your fire is crackling, then you are more likely to get ashes in the water. I found that if I don’t cover my pot, then I’ll be eating ash flavored noodles instead.
First, you want to place your pot directly over the fire in order to get the water boiling. Add about one half cup more water than usual to count for higher temperatures. Next, add in your noodles without any sauce. I found that the sauce can burn quickly and requires lots of stirring. Let the noodles cook until soft. Next, drain the water and add some sauce. If you are backpacking, to save weight, use powder cheese with one cup water left in the pot. Now the sauce just needs to be heated up, and will only take about two minutes. Finally, remove the pot from the fire, to keep from burning, and enjoy.