Sure they are effective. You can make yourself some naturaul ground blinds and be successful without spending anything more than a little time. You will absolutely need to be at least a couple ground blinds, so that you will have a choice of which to use depending on wind direction.
It can be done. Don't think for a second that you have to have a treestand to have success.
You can also use a pop up blind effectively. You will need to blend it in with the surroundings because deer will usually shy away from it if it doesn't blend in.