I sit in front of a large down tree that is high enough so that my outline is completely concealed. I've had deer less than 15yrds away look right towards me and not spot me in full blaze orange. I think the key is managing your scent and movements. Deer's noses are better than their eyes unless when theres movement to pick-up.

So my advice would be to find a large tree whether upright or down that has a larger outline than you have and use it. Also, cover your scent as much as possible and eliminate any human smells as much as possible.

Good Luck!