I think they help in certain situations. The wind needs to be right, like any other time when bow hunting. Many times it'll take the bulls into bow range, when they hold up outside of it. Visual can help a lot.
i've heard both ways good and bad about decoys. My buddy says he's had bulls come into his decoy and sniff it. but last year when we got ahead of the herd and set it up, the elk didn't like it and they booked it in the other direction. i personally dont like to hunt with a decoy because i think i would rather that the elk not know anything is there. i'd rather be fully invisible if that makes sense
We use our decoys in way to keep the bulls looking........we've had good luck with using them in/behind underbrush where only part of the decoy is visible. The Montana cow decoys work well as they are compact and lightweight. I too have had elk get spooked by them as well though........to each his own!
One of the most important components of deciphering a new hunting area is distinguishing between the summer and winter ranges for the game that you plan to pursue. Without knowing this you cannot make reliable assumptions about where the game will be come opening day. Knowing these areas will allow you to take the current weather (as well as the past couple weeks) and apply that to the landscape and make an educated guess as to where you might find that big buck or bull.
There are a couple ways...