Phantom training is not as hard as one might imagine it to be. It involves conditioned reflex response (remember "Pavlov's dogs" from school science?)
The response is of course ejaculation. The condition the stallion must undergo to achieve that is to mount the phantom mare (also known as a breeding mount or dummy) and breed the AV.
Teaching to mount may require the judicious use and placement of a mare in estrus, or it may be achieved in some stallions without the presence of a mare. A lot will depend upon the individual stallion's libido. The stallion should first be "teased" with an estrus mare in a location away from the collection area - in the barn or a tease stall. This serves to indicate to him that he is entering into a sexual situation in which certain behaviours that might not normally be suitable will be tolerated (calling, "strutting", gaining an erection, etc.). It is important to the stallion's mental well-being that sexual behaviours such as this be allowed in a sexual situation - which includes teasing, not only the actual breeding/collection process. As the ultimate aim is to be able to collect the stallion without a mare in the picture (beyond the initial identification stimulus), it is good to start as one wants it to end - without a mare in front of the mount. With some stallions that have a lower libido however, this will not result in sufficient sexual stimulation, in which case an estrus mare is placed in front of the phantom, slightly to one side, usually the off side, as in North America it's commonest for the AV handler to work on the near (left) side. In Europe the AV handler may be seen to work on the far side from the stallion handler, but in out opinion as a general rule it is better that both be on the same side so that the stallion handler can protect the AV handler if the situation gets awkward. With the AV handler on the far side the stallion handler may not be able to see what they are doing and what assistance they require. If the presence of a mare at the mount is necessary, initially it is best to have the mare and stallion facing each other, and only if the stallion continues to be disinterested should one turn the mare so her rear faces him.
The stallion is led to the breeding mount, which should have had a little estrus mare's urine rubbed on the end nearest the stallion (the "back" end), and he should be encouraged to sniff this. It is surprising how often he will mount the phantom once he has sniffed the urine it with no further stimulation, but if he starts to loose interest further measures can be taken to encourage mounting such as bumping his chest against the mount, walking him up to the mount again, and possibly even positioning him in from of the mount and introducing the AV to his penis (be aware that some stallions will then move forward and mount the phantom, which can put the handlers and the AV in a dangerous position - be awake!). If none of these actions bring positive results, then the real mare is moved to regain his attention to the business at hand, possibly reversing her position to have her rear end towards him (hence the importance of using a mare in estrus who is receptive to the stallion's advances), and some "sleight of hand" may be required to achieve mounting of the phantom rather than mounting of the mare!
Usually the stallion will mount after a little encouragement. At this point, his penis should be deflected (not pulled!) towards and into the AV, and he should be allowed to breed the AV. Stallions vary as to how much handling of the penis they will tolerate. Some one can be quite aggressive with, and really "work" the AV, others will not allow this, and will lose their erection, or dismount. Others will be happy to "work" the AV adequately themselves, which is the ideal situation. It is important to watch the stallion and his reactions closely in order to determine what is required. Never think of a stallion as anything but an individual that has individual likes, dislikes and requirements!
The AV handler can check to see if the stallion has ejaculated by feeling the base of the penis for pulsations at the time of the ejaculation. Visually, one can see if the tail is "flagged" (although this is not universal as an indicator of ejaculation), and depending upon what collection equipment is used one may observe the semen filling the container attached to the AV.
It is important to note that while the phantom training process is not difficult, it is essential to get the timing right, the required degree of stimulation with the mare's proximity, and the penis/AV handling and AV setup correct. Without all of these things coming together, there is a good chance the stallion will not ejaculate. If this occurs, then it is possible the exact opposite to that which is desired will happen, and the stallion will have learned that it is not desirable to mount the phantom. For this reason, I suggest that phantom training be undertaken only by those experienced in the method. An experienced stallion handler may make the training process look easy, but do not be misled - although it can be easy, in addition to the the level of libido of the stallion, the experience of the handler will have a direct impact on how easy it appears!
Some stallions will not mount a phantom, and/or ejaculate into an AV. Often these stallions are older stallions who have pasture bred or in-hand bred with minimum human intervention for many years. Collection into an AV can often be accomplished by using a "jump mare" (a mare in estrus who is guaranteed to "stand" well) rather than a breeding mount for these stallions.