I agree with what everyone else has posted but will add my experience for this year's opener. I set my stand up a month before opener in a core area and left it alone until I walked in opening morning. I got to my stand a little more than an hour before sunrise, put out a scent wick and climbed up the stand. Right when I sat down I heard some crashing about 15 yards away from me but couldn't see what it was until he started snorting at me. He snorted 10-12 times really loud and crossed the river - I didn't see him again from that stand. I think he heard my stand creaking as I climbed it and he likely winded me. I practice good scent control but he could probably still smell something that alarmed him.

My best advice is to approach and climb your stand as quietly as possible, be as still as possible once in your stand, and do everything in your power to minimize your human odor. Like White-tail-deer said, make sure the wind is right for the stand before heading out.

Good luck!