I fish trees quite a bit. I pretty much agree with the notion that you fish structure and not the trees.
However, in my experiences, in most of the Missouri Conservation Department lakes that I fish, the fish do suspend in the trees from time to time and they can be caught.
Trees can be cranked. My favorite crank bait for this purpose is a DC16 or a DC 13 Timber Tiger. I'll Generally fish this bait on 15 or 17 lb line. The DC 16 might get down 8 or 9 feet on 17 lb line. What you're looking for is the big horizontal branches that are 5 to 7 feet down. Keeper fish often lurk behind/around these wood features. I guess what they're looking is schools of baitfish swimming by.
For me, this isn't an all day approach. Find a row of trees with features that look ok. Maybe off to the side of a road bed, maybe they turn a corner in a sunken field, maybe overgrowth on the back side of a dam on a sunken pond, something. Throw the Timber Tiger, bump it into stuff, see if you get bit. I tend to get bit more when I can imagine where they shade pockets might be 5 to 7 feet down, as the keeper fish tend to position themselves in the shade pocket, where they can look out into water that has more visibility. THIS DON'T ALWAYS WORK!! I generally give it 15 or 20 minutes and if it ain't happening, it ain't happening. Several times per year though, it produces a 20" or bigger fish.
The classic timber lake in Missouri is Truman Lake. Since that lake was filled, throwing 10" worms in the trees has been a viable approach. As has been mention in prior posts, there are trees that have the potential to produce and other timber areas, not so much.
The approach here is simple. I generally use 20 lb Abrazx, a 10" power worm ( generally Blue Fleck) and a 5/0 hook. Weight varies. Throw the worm kinda close to the tree and let it drop. Hits almost always occur on the drop/ maybe a few seconds after it hits the bottom. Deadsticking the bait or working it all the way back to the boat hasn't worked real well for me. For me the approach is - Do the drop - hit the bottom, one bounce, reel it back fast & repeat.
Other baits might occasionally work - tubes and brush hogs are popular with some guys - the old jig & pig is still popular with other guys. Me - I like the 10" worm.
The other option I'll try in standing time is a wacky senko. I've had years when that was THE ticket, the only thing you had to figure out was were they suspending in the crown of the tree or closer to the trunk.
The last few years, not so much with this bait. I think that it still works but I think that day in & day out the 10" worm ( 5/16 or 3/8 oz tungsten weight, generally) works better for me.
So, there you go, that's how I generally approach standing timber in deeper water.