A light rain or snow is perfect for still-hunting. The precipitation helps hide your sound, scent, and motion, and deer activity often seems to increase in this kind of weather. Windy days are good too; the swaying branches and howling gusts also disguise your presence, but deer won't be moving as much. Look for them in hollows and on the lee sides of hills.
Follow deer tracks you come across in the snow during a still-hunt--even if they are old. The idea is not to target that particular buck but simply to let the trail take you to areas where deer travel and feed. I've discovered some of my most productive hunting spots by letting deer lead me to them.
Look for water. Creekbottoms are great places to still-hunt. Deer often follow the watercourses, and the trails you find parallel to the creek make ideal routes. The water can hide your sound, and cover and food attract deer.
Let yourself get lost. Successful still-hunting takes all your attention--analyzing everything you see, stalking with extreme care. You can't do it if you're constantly worried about where you are. Set your GPS and then lose yourself in the hunt.
Still-hunting is one of the best ways to learn a piece of land, because you're covering ground and doing it at a pace and with a level of concentration that forces you to spot tracks, droppings, rubs, and bedding areas. So keep a map with you, and make notes as you go. I carry a digital camera and snap photos of interesting sign and promising spots. It only takes a few seconds, and when I get home the images remind me of what I saw. I've found great bowhunting stands and other still-hunting routes this way.
Grouse hunters often hit several productive covers in one morning. You can do the same thing if you have a few places to hunt close to one another. Sneak through the brushy bottom next to a field on one farm. Get in the truck and hit a winding creekbottom nearby. This allows you to focus on the best spots in multiple sites.
Maintaining a razor-sharp focus may be the most critical skill in still-hunting. Get distracted and sloppy for a few steps, and you can undo two hours of careful work. If you feel your mind wandering and find yourself going too quickly, take a stand. Eat a sandwich. In 20 minutes, you'll be ready to start again.
Don't avoid dense vegetation. "That's too thick to still-hunt" is something you hear often in deer camp. But if it holds deer, why not give it a shot? You probably just need a different approach. Focus on small cover, just a couple of acres, and really work it over. Spend a lot of time looking, squatting to see under the brush, even crawling. Go very, very slowly.
Before you step into the woods, take the sling off your rifle and stick it in your pack. You'll want it when you drag the buck off the mountain, but if you use it before then, you won't be bringing anything home. Shots are quick in still-hunting, and keeping the rifle slung over your shoulder is the best way to miss.
Stop next to cover. It's one of still-hunting's golden rules. Having a tree next to you when you're not moving helps hide you from deer, and it also gives you a rest in case you need to shoot offhand.
Good binoculars are a still-hunter's best friend. Use them often to pick apart the terrain in front of you. If something seems even slightly off, glass it. Wear them on a harness that holds them snug against your chest so they won't swing when you duck under brush. Bring them to your eyes slowly.
Get a gillie suit. I used to laugh at hunters who wore them. Then I tried one on the recommendation of a friend who successfully still-hunts with a bow. This leafy camouflage outfit hides the two visual clues that I think are the main things that spook deer: the flat, wide-eyed predator's face, and the upright, two-legged silhouette of a man. The very first time I wore one, I crept within bow range of a feeding doe.
To walk quietly, wear boots that fit tightly, with solid support and a thin sole. You need to be able to feel sticks and other debris under your foot before you bring your entire weight down. Put your heel down first, slowly rolling onto the ball of your foot. Gradually increase the pressure, and find another place to step if you feel something underneath.
No matter how hard you try not to, you will snap a branch underfoot. When it happens, just wait a full minute before proceeding. Deer will forget about the noise if you give them enough time. If conditions force me to make a ruckus going through a particular spot, I'll blow a series of grunts on my call, hoping to fool deer into thinking the noise was caused by one of them.
You'll try to find a rest before you shoot at a deer, of course, but when you're still-hunting, most shots are offhand. There is no shortcut to getting good at this. You must practice before the season. Make it a rule that for every round you fire from a bench or rest, you fire two offhand. Shots will most likely be close, so don't set your variable scope any higher than 4X.
There's no need to dress as warmly as you would for a day of late-season stand hunting. You'll perspire in bulky clothes, which also make it harder for you to move quietly. I wear a synthetic base layer under a medium-weight wool jacket and pants. Nothing is quieter than wool.
Wear a fanny pack to bring lunch, water, a survival kit, and extra clothes. A backpack is too noisy for still-hunting; it always ends up raking across branches or brush. I prefer a fanny pack's lower profile. A model with shoulder straps supports the load better and is more comfortable to wear all day.