I'm blessed to hunt in the Texas Hill Country, where there are tons of deer. One thing I've learned (the hard way
)is that just because you've got your stand set right in relation to the wind, made your approach as carefully an quietly as possible (always watching the wind, always!)and you've got a nice buck coming your way through the mesquite, upwind of you, and have done everything else as nearly perfect as possible, doesn't guarantee a thing. Invaribly, a little doe is going to slip up behind, or maybe just wander a little too close to you, and She'll spook, along with every other deer for 1/2 a mile (AAAAARGGGHH!!!!, Damn I LOVE THIS SPORT!).
This was with no cover scent.
Now I use liberal amounts of the spray-on scent eliminator/Fresh Earth cover scent (from Wal-Mart, Academy, etc.), and a good dose of Coon or Red Fox urine. Then as I go out in the field, I try not to miss anything stinky to step in (cow patties, etc), as well as anything else natural that helps cover my scent. I'll use leaves, cactus (watch the thorns), soil, or whatever else is around. My goal here is to get as much "normal" scents for deer going as I can.
Since doing this, I've had deer come within 5-10 yards of me without spooking. I had 2 does last weekend come about 7 yards from me (I was standing, stone still, next to a little oak tree). When they got down wind, It was obvious they got the smell of something they weren't too sure of, and they eventually wandered off. BUT, they didn't spook, and MORE IMPORTANTLY, they didn't spook the nice buck I was watching (who I BEAT by getting within 10 yards of, but was just a tad too small for my last buck tag, with a month left in the season. He's still walking, and doing a fair amount of work passing on those genes