You should play it cheeks blown up, with the reed free in the center of your mouth cavity.
The high pressure needed to get the sound makes it hard to keep lips tight together over longer stretches. The lips need support from a device like a pacifier diaphragm. as the one here to the right.
You can control the exact frequency you get from any key by controlling the air pressure applied.
The finger holes are wide. That gives you the possibility to get any note by opening your finger just as much as needed
This double control of the frequency both by air pressure and by finger aperture makes zurna a highly controllable by the expert but also highly inaccurate for the new beginner type of instrument. The scale is therefore any scale you can recollect and regenerate.

Transposition is done just like with the flute, not like the clarinet as one might easily think it should be.
Tweaking of the reed: make it wet. make sure there are no cracks/leaks along the reed fiber. Make sure it is almost closed at the tip and has a resistance to complete closure.
Tuning: The length of the reed conus must be adjusted. Some degree of tuning may be found there. Adjusting the reed distance to the first hole is usually done by adding/removing wrapping thread at the base of the metal pipe where the reed is attached. The small holes at the bell might have to be closed or opened to change the timbre/last tone.
The holes should be placed to give the scale that YOU need. If the holes are not correctly placed you will still be able to get your scale by using semi open holes and air pressure variations. In the long run you might notice that they do affect your playing comfort.

Specially if a hole is misplaced, getting that note right will be difficult, as it will require sudden changes in air pressure and fine control of finger aperture, several places under a melody that can otherwise be played relatively care-free.
In my case the scale has the pause tone at re(D) and has the aproximate interval structure of the white keys in a piano when the pause tone is placed at re(D).

The in between tones(commas,fractions etc..) must be adjusted by the ear while playing. Zurna can not trust the zurna to give a precise tone each time; you must trust your ears, fingers and breath. It is therefore that one plays a rithmless prelude before a song/session in a given scale just to get the ear ready for that scale.
If you want to train your ear, you may want to hear the tones from a precise instrument. A good approximation (some say the true frequencies) for the tones used in middle eastern music are calculated by dividing an octave in 53 equal intervals (12 i piano/72 in south indian music) whose frequency ratios are given by the following formula
(2**(1/53))**i ( (2**(1/12))**i in piano ) and chosing the following 7 (from low re to high re):
0,9,13,22,31,40,44,53 (0,2,3,5,7,9,10,12 in piano)
Another scale would be a different set of 7 numbers.

This scale is called “hüseynî” or “divan” in turkish. There are some 200 such scales picked from the set of 53, A dozen of them are the usual ones. Hüseynî makami(/divan ayagi) is the most usual and probably accounts for more than half of all turkish folk songs. That is the reason for tuning the turkish zurna to it.
Common fingering: lower thumb and upper little finger are free. The other 8 fingers cover the 8 holes of the zurna. Pause tone (La/A or Re/D) is obtained by opening the lowest two fingers.
Sound effects:
vibrato: by fluctuating pressure in the mouth
ritm: by flashing/tapping the uppermost open hole.
tone shifts: either sliding by gradual opening or closure of the finger, or accompanied by tapping of the hole below or accompanied by flashing of the hole a few fingers above.
These may not apply to zurna types and zurna music that I am not familiar with.
The shape of the instruments internal cavity is like a parabole and therefore optimized to send the voice straigh ahead. You will notice it very well if a zurna player turns your way.]]