What exactly are psionic powers?
Psionic powers border on innate abilities and learned abilities. Because of this there is much dispute on how much prep a psionic power requires. Please take this into consideration, an innate ability is something you are born with, a latent would be something you train to do until it becomes second nature, like a martial; artist that will throw a hammer block up if he was being attacked with an axe kick, it is all reflex action. I believe that only certain psionic abilities are innate, such as a burster using pyrokinesis. With this in mind realize that some powers are learned over years of work and training, such as a Mind Melter who learns to use his Psi-Sword, they must have so much experience to use such a fearful weapon. Keep in mind that a psionist is born, not made. With that in mind comes the next section.
Psionic Prep Considerations
With this out in the open think of two psionic abilities, a telekinetic lift on a 5 pound object and the same lift on a 10 pound object, it simply takes more concentration to move the objects. This runs into the area of what would take what on prep, would a small fireball ignited using pyrokinesis take more concentration or would igniting an entire room? of course the room because it is a broader area to ignite. With this in the open consider a minor thing such as a bio-regeneration(a self heal) as compared to a mind wipe, I would say the bio-regen would take less prep, coming in at about 4 to 5 lines of prep as compared to a mind whipe, which should come in at about 12-15 lines total... remember you must first take control of their mind which could make the entire mind whipe take almost 30 lines in preperation altogether. For such powerful beings they can often be slaughtered with relative ease. Also note that a psionic ability must be focused witht he mind and breaking that focus or concentration means the psionist must start over again!
Basic Rules and a Numbered Steb By Step Listing of Using Psi.
1) Always prep, and consider the power of the psionic ability to determine the number of preps required.
2) The psionic ability can be canceled by another breaking the psionists concentration or the psionist themselves.
3) DESCRIBE the psionic power being used, will it kill, does it push someone do you simply make a sword... all of these things must be described in the preperation.
4) BE vivid in your description, don't just say that your character focuses on a psionic ability, state what he does during the focus.
5) When you prep remember to focus the psionic energy first, if you don't focus it what are you using to cause the psionic effect?
6) Remember to narrow your focus on a single power, you cannot prep more than one ability at a time... it is near impossible and only a very powerful psionist can do such things.