I feel bad in saying this, but two things stand out: When you're first on the ground, and how much you seem to be moving.
Right now, mid-September? This isn't "early in the season" for finding bucks - it's way late in the game. Don't let this de-motivate you, but it's important to know. If at all possible, unless there's a really big migration in your zone, it's best to be scouting as early as mid-late May and all through June, when their coats are red and they just stand out much better visually. When in velvet bucks tend to bachelor-group up more out in the open (but in the shade), to protect their antlers while they're softer and more easily damaged. They're relying more on a type of group security, even older mature ones. You want to know exactly where they are when they're red and in velvet. When they go hard horn is also about the time their coats go gray-ghost, and they go deeper into the brush when and often "disappear". That's a rookie mistake to assume they're gone though - they're still in that same general area as long as there's still food there, they're just more alert, more wary, and physically harder to see from mid-Sept onward.
Second, is that if you're seeing all those does, but not seeing bucks, that's because the bucks are seeing/hearing/smelling you. The more sparse the food plots are in that geography, the more true that will be, because they're all racing against winter to pack on the pounds, and need to eat pretty much the same thing. The bucks will tend to be higher than the does during the day, however, in the shade, with a great view of everything below them. If you're just kind of walking from place to place, trying to turn up a buck - especially bowhunting - it's not a very high-success approach. That's like walking around a neighborhood, hoping to run into the exact person on the street you're hoping to run into. Instead, you want to know their exact address - and that's what scouting is for. Finding their house.
For better success, and regarding what to do right now in mid-sept to find bucks now that they're largely transitioned to gray and are starting to transition from velvet to hard-horn, try some version of this formula:
1) Use OnX or other hunt mapping software, and find the food. You may have to google around to find out what they're eating this time of year in your specific geography, but if you're in desert D zone areas, look for the green on the maps. When you find promising stands of green (especially those in low spots, with higher rock outcroppings around), drop pins on those, and map out a good part of the area you want to hunt.
2) Look for access routes into those areas, and use the route-mapping tool to lay out your intended path by vehicle.
3) Within that area and relative to your access, start mapping out good glassing spots over those food sources. Very specific, deliberate spots you want to glass, and where you want to glass from. Then use the route-mapping tool to draw yourself a very specific route from one glassing spot to another. This way you're not wandering around, but are very specifically focused on sneaking from one spot to another.
4) Be at the first glassing spot at least 30 minute before light.
5) NEVER, ever skyline yourself. Sneak over any crests by crawling below brush-height, and set up your glassing site below the visual crest of the hill. You want deer to only see brush, rock, or dirt behind you, from any angle. Even better if you can find a place in the shadows, both for extra difficulty in being seen, and for your own personal comfort.
6) Hunt high, hunt the shade. Think of the sun as a magic death ray to desert deer - they're very averse to it, and live in the shade during the day to avoid it. The only time you'll usually see them during the day (besides being bumped) is when they're getting up to adjust their bed to get out of the sun that has shifted on them. Look for higher locations around you, especially north-facing slopes, that will be in the shade all day.
7) When glassing, adjust your position 10-20 feet in any direction once or twice before leaving, after you've glassed for awhile - it's common to have things like antler tines, ear-tips, and hooves appear just by moving two or three feet left or right. Deliberately changing position 10-20 feet at least once per glassing spot is good procedure.
8) Sneak in and out of each glassing spot, and go slow.
9) The wind rules everything - always be hyper aware of its direction. You can often fool a buck's eyes, and sometimes their ears, but you will never, ever fool their nose.
There are a lot more fine points, but that's a pretty good template. The only major adjustment I personally make to any of what you see above, is at the first of my pre-season scouting, which is off the table for you this year. What I do after mapping out the food plots is to actually get down into them on foot, and scout like crazy for any sign of deer. Paying particular attention to the big, blocky prints of big, older, heavier bucks. Depending on the zone's geography, I'll hit up to a dozen a day sometimes, just looking for sign - and cover a heck of a lot more territory than if I was just glassing. I'm not worried about bumping anything, because anything big that might be there will be there when I come back weeks or months later. But what it also does is rule out places mountain lions have been haunting. There's been way too many times I've gone into absolutely amazing feed plots, only to find zero deer sign, but do find cat prints.
