Years ago I drug out a hooter shooter that had never been used out of storage at my bow shop I shoot for.  I spent years fighting with it and learning how to group tune arrows and in the end it has turned out to be a sweet tool to really tighten up my shooting.  The hooter shooter is poorly designed in many ways and figuring out the tricks to make it shoot same hole accuracy is a long process.  Below is a list of the things that I have learned that allow me to group tune my arrows .

Technical Stuff:

1.  Draw Stop:  the hooter shooter doesn't come with a draw stop so you need to make one,  use a radiator hose clamp and a pipe that is the same size as the tubes that the release assembly slide on.  Cut the pipe and get a 1 inch piece and cut it in half and place it on the pipe and but the clamp on,  get one of the clamps at the auto parts store that has the little finger tighten handle and now you can easily loosen and slide it to your setting easily.
2.   Grip Tape:  Leave the grip tape on your bow if you use it and it assists you as you sight in the bow every shot because you will need to twist on the bow a little when you come to full draw and the grip tape grabs the hooter shooter and stays there so you can make little adjustments.  If you don't have grip tape on your bow it will be to slick and hard to aim.  I would get some black tape and put a layer and then put duck tape over it,  the black tape keeps the duck tape from leaving a bunch of sticky stuff on your grip.
3. Laser Beam:,  This is beyond important and required,  get yourself a laser beam and figure out how to mount it to the bow.  Using a bolt that threads into the front stab hole is a good option or you can just tape it to the stab.  Ours is a laser for a gun and it bolts onto the scope rod.  Now,  how to use it.  Put a piece of cardboard about 6 feet in front of the bow and off to the side so the arrow doesn't hit it and draw the bow back without a arrow and let the laser settle into the cardboard.  Then take a arrow or a pencil and make a hole in the cardboard right there.  In the beginning we would make a sharpie mark and match up the mark with the laser but then one day we made the hole with the pencil and now the laser vanishes in the hole and makes aiming the bow so much easier.
4. Nock Sets:  We have found that any extra gap between the nock and the nock sets or the knots if you don't use nock sets or nock pinch will screw up the arrow and not allow you to shoot the same hole accuracy.  So we now bring the bow back to full draw and we check to see that our nock sets are touching the nock so there is no gap at all and also no nock pinch.  Just lightly touching.
5. Release:  Our hooter shooter came with a firday night delight thumb trigger and we simply trigger it with our fingers and do not use the 2 ft long trigger they offer.   I also put in a washer on the pivot joint so I could lock up the release holder so that it stays put and I have marks  that show it is in the right location.  This helps aiming with the laser for it to not move much and be able to put some pressure on it and move it a little and it stays right there.   We also figured out how to use some paracord and make a safety so that we can use the hooter shooter as a draw board without a arrow.
6. Sand Bags,  I got 3 50 lb sand bags and they are what I weight down the hooter shooter with.  They seem to be enough to keep it from moving but sometimes it does move.
7. Platform,  In the beginning I just laid the sand bags on the legs of the hooter shooter but then we got a couple 2x4's and we screwed them together making a T on the floor and screwed down the hooter shooter to it.  So now we can lay the sand on the T and hold down the hooter shooter and it doesn't move around at all.

Method:

So,  I have learned to strip the fletching off my arrows and do this as bare shafts or just do it with new shafts before fletching them.  I bare shaft tune my bow with the competitive tuning article and that is done with one of the shafts only.  Then I set up the hooter shooter and I use that shaft and I shoot until I get it where it is shooting the same hole accuracy.  Now for the important part,  I number the arrows with little tally marks with a pencil back on the shaft by the nock.  I then put up a new piece of cardboard and shoot each one of the arrows and mark each of the holes in the cardboard with its number.  Once I am done shooting each shaft I can then see the group size of those shafts right out of the box with no tuning done.  I pick the central arrow as my new control arrow and I am going to tune all of my arrows to that one since it is in the center.  Now if I have a bunch of arrows that already hit the same hole with no tuning needed then I will allow that to be my control arrow location.  So lets say that I have 8 arrows to group to the same hole and 5 of them hit the same hole at 20 yards.  Those arrows are done and I only have 3 arrows to turn the nock and move over to that hole.  This approach makes tuning a group of arrows so much easier than randomly picking a control arrow.

Buddy:

I like to have a buddy,  his job is to go get the arrow while I reset the shooting machine,  In the time he goes and comes back I can have the bow half drawn,  I then stick in the arrow and finish drawing.  I don't draw all the way because I am working so fast that hitting a trigger would blow up the bow but at half or slightly less than half the bow will survive and it is easy to load a arrow and do a couple cranks and shoot.