Year in and year out, my go to baits for largemouth in the fall have been jigs.
Either a white or bluegill swimming jig with a rage grub trailer on days they want to chase.....1/4 oz on the bank, 3/8's oz over the grass, and 1/2 oz along the deep weed edge...........I'll go with a chatter bait in dirty water. In the fall around here, sometimes the grass gets funky, and swim jigs come through better, where as cranks.........while a go to, often will just wad up, and not pop free out of this fragile grass.....every year is different, some years the grass remains hearty well into late fall, other years, like this year, it started getting mushy and difficult to fish treble hooked baits around as early as mid sept.
As the water temps fall and the bass move from deep to mid depth, to shallow, and then back out again I follow them with different weights and styles of jigs/trailers
In early fall, before they start moving up, and water temps are going down slow, I will start on the deep grass line of hard offshore cover with a 3/4 oz football jig with a 4" chigger craw trailer. Either in black/blue, or a green/brown depending on water color/light conditions. As they move back into the mid depth grass, it's hard to beat ol'reliable............the 1/2 oz. flipping jig in the same colors, with the same trailer..........that is IF the jig is heavy enough to get through the grass, sometimes I have to bump it up to a 3/4 or 1oz............and also the clearer the water the heavier I go............faster is better in clear water. When they have moved to the inside grass line, up under boat docks, and other bank cover like laydowns, etc....I go with a 7/16 finesse flipping jig with a 3" chigger craw trailer.
As water temps start falling more rapidly, and they start reversing this movement, I again make adjustments to my jigs.............the shallow jigs get downsized to a 5/16oz, and I put a more subtle trailer on, like the small Havoc pit boss or the small yum craw bug, the 7/16 oz finesse flipping jig now gets the call in the thinned out grass, with the same subtle trailers, and the deeper grass lines, and offshore stuff get targeted with a 1/2 oz football jigs trimmed and thinned to be more compact..if I can get away with it. If the winds blowing or I am having trouble keeping bottom contact, I'll bump back up to 3/4's oz, but thin and trim that jig up as well. I also go with a smaller subtle trailer here too.
I use other stuff.........sometimes quite often, as there are days when they just don't want to bite a jig very well. But year in year out, a jig in some form or another would be the only type or bait I would use in the fall if I had to pick just one.
For smallmouth, I consider the fall bite to be on here when they are grouped up again, and back in realatively shallow water (for them), which is less than 20', and usually not much shallow than 8-10 feet.
On calm clear days, I like to poke around in these depths with 4" stick baits on wacky jigs, or something nose hooked on a drop shot, and some top water or suspending jerkbaits early in the AM and late in the evening. When the wind picks up, and the clouds roll in, cranking with a 3xd or 5xd works well, or the old "drift and drag" over/through smallmouth holding areas with wobble style football heads with a chigger craw or pit boss, dragging a tube on the bottom, or drifting with a drop shot put fish in the boat for me. Swimming a grub on ball head is another old school technique that works really well for me on fall smallmouth. It's about as simple as it gets, thread a 4" grub on a 3/8's head, cast it out as far as you can on spinning gear, let it sink to the bottom, and just reel it back in nice and steady.
As the water temps reach the point of no return in the late fall/early winter and the largemouth action all but grinds to a halt for me, I reach for a silver buddy style blade bait, and fish those in the same areas, at different depths until I find out where they are that day. I am a noob with these, but in the last 2 years, they have been a go to in both late fall before ice up, and early spring after ice out........they catch everything in the lake, and work when nothing else will.