The big things for me when walking are:
1) Having a strong wind blowing into you, covering your noise.
2) prep your gear/clothing so when you move it doesn't make noise. (Fleece)
3) Don't look for a deer per say, Depending on if your hunting thick bush look for movement, tails, antlers, hooves.
4) Stop often look and listen- moving 10 yards can change your periferals (Don't know if I'm spelling that right).
5) mono-pod! the buck I posted a picture of in the "Good-bye hunting spot" thread was taking with a mono-pod rest (one-hand adjustable) at 60 yrds, I heard him before I could see him and when he lifted his head from making a scrape I had to shoot through two poplars with about a 6-10inch gap between them, only clear shot I could take was at the white patch under the chin (Slightly quartered too me). it was either that or the head. Too much brush lower.
I'm no expert It's just when I started hunting when I was younger I would get bored easy, I didn't like sitting with other people (Youth hunting suppose to be within x-amount of distance of mentor) so I'd just grab a radio and go for a walk. My dad's friend frequently shoots deer like this, It really takes a good eye, When he drops us off into our "Spots" where we are going to spend the morning he is always seeing deer way the hell back in the bush when we are driving. (And no we are not road hunters :lol: )
I was thinking about doing this for fall bear, Found a spot where I frequently see bears going in and out of a bean field, One day when grouse hunting I saw one in the corner of the field eating so I ditched the truck and crept in the ditch and got within 50 yards just to sate my curiousity the figured that was close enough I think it would be an interesting concept....actually saw a show (I think Canada in the Rough?) where they were hunting bears like this in B.C or some such.