How do you keep groundsheet in place.

I want to try a piece of poly ground sheet, but I will be using it under a tent probably. So, the tent will hold it in place. But I guess if I were to use it under my tarp, I could reinforce the corners with a little tape and than put a small grommet which I could then stake down. Sure others will have better ideas…

The groundsheet I use is small. Just big enough for me, my pack, and my shoes. As a result, I tend to keep it in place pretty well. If I were using a bigger one, I'd probably use rocks to weight it down.

Rocks or sticks at the corners. Pad, bag,gear in the middle. Don't over complicate things with grommets unless you are expecting lots of wind while you are base camping and out exploring.

There's no need to secure it once it's under my tent when there's gear in it. I did attach loops to the corner and put my stakes in it while I'm setting up. Once my tent is mostly standing I'll throw my gear inside and remove the stakes from the groundsheet and use them to finish guying out my tent. If I had a tent with a traditional bathtub floor, I'd probably tape or velcro it to the bottom. Wait, I do have a tradtional tent, but I haven't done that with it…maybe with my next one.

I have a custom 5'10", 220 pound weight that keeps it nicely in place :)

Groundsheets may be slippery on the top, allowing you to slide down on a slope, but I haven't had a problem with the sheet sliding on the ground.

I use a 7×3' piece of tyvek for my ground cloth and I actually use pieces of gear or rocks to keep it from blowing around. The first time I used it was in Big Bend while hiking the Outer Mountain Loop. A rock on each corner did the trick and we experienced some hardcore wind the last night in the Chisos.

When I used Polycro in the Gila Wilderness it didn't seem to slide at all. If anything it stuck. I did use gear though on the corners and that did the trick.