This is an idea I had out of the blue after a friend gave me some broken supercheap headsets. It's a modular microphone that can be magnetically attached to almost any headphone (I like this because I can do gaming with high res headphones and also use them for music. Yes, audiophilic here).
For this you will need:
double sided sticky tape (mine is a kinda gummy soft tape that is just gentle and doesn't damage the surface, I recommend using one like this)
a microphone from a headset (I extracted one from a really cheap headset but you can use an expensive one, if you got the guts)
a headphone cable (preferably a light one, I could also teach how to build one from basic components, comment if you want that tutorial)
4 round shaped neodymium magnets
Step 1: File Out the Microphone Until the Base Is Flat
I used a dremmel for the rough work and later used a metal file to flaten everything down.
Note: it needs to be as flat as possible to attach with stability.
Step 2: Put 4 Drops of Glue on These Spots
Step 3: Join Two Magnets Together and Glue Them Into the Microphone
You want to make sure the magnets are aligned with the microphone's rod (if you do it without that you'll make people freakout when looking at the magnets on your headphone and they will SURELY remove your magnets).
Note: be sure that the cable is down to the correct side. I ike using mine on the left side, so it has to be facing down when it's on the left.
Step 4: Take Two More Magnets and Place Them on the Tape You Are Using and Trim Off Excess
They have to be opposite to each other, be careful with that.
Step 5: Place Then Over the Magnets on the Microphone (after the Glue Dried Up) and Peel Off the Protective Film.
I like to use thin tip tweezers for this.
Step 6: Push It Down on Your Headphone's Back to Glue the Magnets
Please try to center it, again, people will want to rip them off if they are not centered properly and I will be agonized to know there is an aberration like that on earth.
Step 7: Now It All Comes to Soldering a Cable Onto the Microphone
It has to be a lightweight cable, otherwise it will fall off.
you can use a in ear cable or make your own cable.
(I like using an extension taped to my table so a short cable doesn't bother me)
Step 8: Congrats, Now You Got a Headphone With a Removable Microphone
Note: I only tested this out on two headphone (akg k414p and takstar pro 82) and had no troubles with the sound or damage to the cans, but this may vary to each headphone or tape you use, so be careful.
I do not take responsability for any damage you do to your material, so be careful.