Well, the OP did say "natural ground blinds" and as a public land hunter, WI. defines a natural blind on public land as one made out of naturally occurring vegetation in the area. On private property anything goes, but not so on the state land. The best one that I've found lately is a big fallen tree with a big root ball that I'm going to use this bow season. I'm not sure a fox hole would be considered "natural" but I've dug in a few of those for dad and his buddies and they hide a guy really well below ground. The problem using evergreen branches is that they turn brown and drop their needles after a year. One of my better hides has been cutting up an artificial Christmas tree, through far from being natural. Honestly a roll up turkey blind works pretty well and I've had deer walk by those pretty close. I get seen and sniffed way more often from any ground blind than I do from a tree stand.
Downed trees are great. If you can sit on the trunk with your back against the roots, it gets you up a bit for a better view and the roots provide back cover and a backrest.
There’s a rocky knob near “my spot” on public land that has lots of natural seats and great views of a little valley and the opposite ridge. Spots like that help keep Grandpa outta trees, a good thing as he probably don’t bounce so good.
