I realize this could be a very complex posting, but here goes
Just wondering what the average Joe could do his or herself to improve these attributes
So thinking proper Cork adjustment.
Oil the Bore.
Now here is a grey area I think in terms of DYI and that is smoothing a Bore if its rough.
in the absence of a lathe could one wrap sand paper around a dowel which is the itself close to the diameter of the bore, or if its tapered using several different dowels. And if you do this what number sandpaper or maybe steel wood to use or increments?
And what about sealing the Bore… that doesn’t seem like something I would care to try myself
Of course the big question when to call in a Repair Person to do other things, or even the aformentioned ideas
Assumptions in my case
Flute keyless with out a slide
Maple or Blackwood
So really what could you do on your own without getting into trouble? 
On my own?
Check for leaks, including around the tuning slide (when present).
Check & adjust cork position, which can affect tone, but can also affect tuning.
Oil the bore.
Learn to play, including direction of airstream into the embouchure, and covering the toneholes well.
Mmmm - Maple? Kind of porous unless sealed.
There is a saying that surfaces here occasionally. ‘What is the most beautiful sounding flute in the world? The one you play two hours a day.’
Love it, practice makes perfect.. well at least some of the time 
There was a long thread recently about bore smoothness and its relative importance:
https://forums.chiffandfipple.com/t/bore-roughness-and-tone/103845/1
I came away from it without any change in my thinking that the bore of a wooden flute with proper maintenance is smooth enough for good tone and volume, and doesn’t need drastic measures to increase the smoothness (others here may disagree). The light sheen of moisture that collects inside the barrel after playing for a few minutes probably helps. As I said in that earlier thread, if a surface smoother than bare wood had appreciable benefits then everybody would be using a 19th Century-style metal lined headjoint, and that doesn’t seem to be a popular option these days.
Getting away from the subject of bore smoothness, the best thing I did myself to improve the tone and volume of my flute was learning how to check for leaks and fix them.
I was flummoxed for a while with my flute sounding a bit weak until I discovered that the headjoint stopper (not actually a cork in my Aebi flute) was leaking. I pulled it, made a better seal, and there was a noticeable improvement in tone and volume. I’ve also learned how to re-pad my keys, fixing a leaky Cnat pad. On a keyed flute, you really have to stay on top of pad leaks, weak springs etc., and at least the pads are possible to fix yourself. Just to make sure and check for any recurring issues, I recently bought a “leak light,” a thin strip of LEDs that can be inserted to check for leaks. Ideally I’d like a magnehelic-whatsis machine for testing, but that’s more money than I want to spend right now.
I know you were asking about a keyless flute, but I though I’d add this about leaks because you can get leaks from tenons, micro cracks and the headjoint stopper in a keyless flute. Paying attention to this has been the main thing I’ve done to improve the performance of my flute.
[quote=kkrell post_id=1249696 time=16356968
Mmmm - Maple? Kind of porous unless sealed.
[/quote]
Was wondering about the density of Maple
I think we’ve had comparative charts of the densities of various woods on the board
If memory serves me correct about various woods Blackwood is probably the most dense, Boxwood is up there, Rosewood depending on which it is is less. Maple I think is yes less dense
If you don’t use a chart. does the weight of a flute with a lot metal give you an idea of density?
My Clarinet repair Lady uses one of the Light Leak LED Tools…pretty cool and revealing
In regards to the effects of metal in the Bore there’s this… I had a Blackwood Bagpipe Practice chanter and the top section cracked from Moisture and hot air. a repair person glued the crack, and put a brass sleeve that was inserted in the bore of the top section. It has not cracked since, but I think the Chanter sounded better prior to the placement of the brass Sleeve
But on the other hand you’ve got metal Boehm Flutes that can sound quite beautiful in the Hands of a great Performer
I think those are more helpful for spotting leaks at the pads, or through cracks. I just use a suck test for keyless, and for tuning slides. On keyed flutes, except for the low C & C# keys (normally open), the other keys are closed when not in use. You can rubber band the lower 2 and suck to test.
Yeah, leaks, and micro leaks, and leaks where you didn’t think they would be. I think that small cracks are often filled when your flute is freshly oiled, or even when the condensation starts to collect.
This practice has been extremely beneficial for strengthening my tone:
Playing the harmonics: D d a d’, E e b e’, etc…
Was wondering about the density of Maple
I think we’ve had comparative charts of the densities of various woods on the board
If memory serves me correct about various woods Blackwood is probably the most dense, Boxwood is up there, Rosewood depending on which it is is less. Maple I think is yes less dense
If you don’t use a chart. does the weight of a flute with a lot metal give you an idea of density?
There are other characteristics of woods besides their weight. Check out the Wood Database
https://www.wood-database.com
or their book on Amazon
https://www.amazon.com/dp/0982246064
Less high tech than these Instrument Lights with Clarinets, you can blow into the left or right hand section, keys down ,palm of Hand covering the lower opening of the Bore ( to check for leaks), not sure which is more effective
So can a rough Flute bore then be smoothed by hand, dowel and sandpaper without a Lathe?
And how do you seal a bore? or would you even know if a Wood Flute has been sealed? How can you tell?
I think if you come across a flute bore that has become very roughened, you could conclude that it hadn’t been sealed, or at least hadn’t been successfully sealed.
To your list of things to check from time-to-time, or at least when you start to worry “is it me or is it the flute?”, I’d add cleaning away any accretions in and around the embouchure hole. I have come across flutes with a good build-up there, and carefully cleaning it away has returned the “edge” the flute was noticeably missing.
(I should probably have collected and submitted a biopsy for pathological analysis. I imagine Guinness DNA could be present…)
You obviously have to be careful here - you don’t want to go at it with your trusty pen-knife, the one you stabbed the wild boar with (reminds me, must get around to cleaning that blade some time…). The job isn’t refashioning the embouchure hole, rather it is restoring it to original condition.
I agree with what Jim Stone said. He’s been playing a while.
Fifty years ago I discovered a sure-fire way to make my flute sound better: play it more.
Only mentioning that which hasn’t been written already:
(1) You can increase the volume by blowing louder (if the flute will support this). Since this takes more air, you need to get more air into your lungs. Do this by playing the low D for as long as you can and timing yourself. You can also do breathing exercises. Also working on focussing your tone (i.e. improving your embouchure).
(2) However, to a very large extent, volume is determined by tone hole and embouchure hole size. If after working on (1) for awhile, you are still unsatisfied with your volume, then you probably need a larger-holed flute.
(3) To improve your tone, play lots of slow airs and songs. Also play long tones on the lower notes, listening carefully to the sound. Experiment with placement of the outer edge of the embouchure hole relative to the centre of the tone holes.
(4) I’m not sure what you mean by ‘improve the playability’. Given that the flute is keyless, there isn’t a lot you can do other than the few things which you yourself have already suggested.
(5) Provide yourself with a flute by a well-known, respected maker.
Chet