~DO NOT~ use screws, this only causes them to crack. it looks like it works, but before you know it, a chunk will just fall out. this happend to me, and not i find the best way in the winter is dig a little trench, shove the pvc in, so its a bout half or 2 thirds out of the ground, and pack snow around the edges, this works really well and the pvc will not move. also try and do it as early as u can in the season, because itll freeze that way. only problem with that is that now it wont move around to set up other stuff. in the summer, your best to just find a flat spot, and drive some spikes (with rounded tops so you dont wreck your skis) as closly to the pvc as possible. this way it wont move side to side, and you can drill some spikes into the ground at the front if its moving forward on you. The pvc might rotate if you step on it with shoes or whatever, but it doesnt matter when you ski, you wont even notice anything trust me. hope this helps!!