After making sure that you are in a dry, high spot, find something solid such as a tree of a big rock. The easiest and most effective way to start is to grab a long branch, almost 1 1/2 times your size and lay it at a 20 or 30 degree angle. You will need to find a way to hold it to the tree or rock. Maybe there's a indentation that you could lay it on or you can just create your own holder. Next you need to build the walls by leaning branches against your main branch. Laura suggests leaving the "studs" of the walls with a little space in between, but I think you should put them as close together as possible... That is, if you have the resources to do so. After the walls are constructed, you should make sure your shelter is the right size by crawling inside it. Now you can start to pile on some small branches and brush as insulation and to protect from rain or snow. If the weather looks good, you do not have to go crazy on this step. Pine and cedar tree branches work very well for this; they help to get rid of any precipitation that may fall. Large, flat pieces of tree bark also do the job, but only pick them up if they are on a dead or fallen tree as you do not want to go around killing trees unless you are in a true survival situation. The last step is to cover the insulation with solid items like branches if there is any chance of wind blowing.
In grade ten, me and a couple others built a shelter like this one. It was very stable and could withstand everything the weather threw at it. We knew that because it had started to snow as we were finishing it.
Gunion, Laura. (2010) How to build survival shelter. Retrieved November 28th, 2014.