I do it without a dog - not as well as those with good dogs, but I do enjoy it and have some success.
A couple tips:
If you're walking a woods road or trail, look for places where they can come to "gravel", i.e., get some grit for their crops. They will be there mid- to late-afternoon. Mark those places in your mental map to come back to. I could have jumped one Saturday but for he was 150 yards down the trail when I saw him and saw me at 125.
Moving slowly helps. They'll often try to sneak off rather than outright run. You likely won't see them when they hold, but you can see them when they move.
Stopping and listening is key: not only can you hear them cheeping sometimes, but you should also listen for drumming. They can and do drum even during the hunting season. Similarly, if you can find a drumming log, it's a good place to visit.
Stopping and turning around is also critical. More than once I've had them wait in thick cover alongside a trail for me to pass, then cross the trail after I went by. There was once in a dusting of snow two sets of tracks alongside each other where a pair crossed less than 50 yards behind me. I followed those tracks through the cover good 75 yards until they flushed out of range.
First snow is very useful They don't remember it from last year. And you can track them.
Birches near pines and pines near birches are always good places to look. Later in the season, especially in cold snowy weather, they will "bud" the birches and fill their crop, then go into the pines to work on their meal.
Old apple trees, crabapples, grapes, strawberry leaves, raspberry/blackberry leaves - all the places to look. Old orchards a great place.
Use stronger loads - if they're wounded they'll crawl under things like logs and such - finding them is where a dog comes in real handy. You want them to hit the ground dead.