How about this:
Seeds get 6 dots to spend on Reflections upon character creation. All Reflections start out with a base Dot rating of 0.
For example, Finder has the Reflection Mandrake's Scream, which inflicts indiscriminate Lethal damage to anyone who hears him speak. Dealing Lethal damage is a +X modifier on the Reflections table, which gives the Reflection a total rating of X dots. However, it has a simple trigger (Finder must be able to speak to use his power, and anyone who plugs their ears is able to resist it), resulting in a -Y modifier, for a final Reflection rating of X-Y dots.
This will not be exhaustive, of course; it'll merely be there to give GMs an idea of where to start, and provide ready-made ratings for some of the sample powers we give them. Comments?
Adds Soak: +1 for Bashing, +2 for Lethal, +3 for Aggravated
The Seed is somehow tougher than a normal human being, either through the addition of armor or shielding or the reinforcement of mundane flesh. Soak added is equal to the Seed's Mythos.
Aspect Reflection: +1
The Reflection in question is "always on", and cannot be dispelled or "turned off".
Augments Attribute: +1 per Attribute augmented, minimum of +1
The character is exceptionally gifted in one particular area of the (in)human experience. All rolls involving the Attribute in question receive a bonus equal to the character's Mythos.
Augments Ability: +1 per 2 Abilities augmented, minimum of +1
The character is especially good at a certain task or tasks. All rolls involving the Abilities in question receive a bonus equal to the character's Mythos.
Deals Damage: +1 for Bashing, +2 for Lethal, +3 for Aggravated
The character possesses a means of unarmed attack above and beyond the human norm. The base damage of such an attack is equal to the character's Mythos, though depending on the nature of the attack the damage might be increased by expenditures of Memory.
Debilitates Ability: +1 per 2 Abilities decreased, minimum of +1
The character can somehow render victims less adept at certain tasks. All rolls involving the Abilities in question receive a penalty equal to the character's Mythos.
Debilitates Attribute: +1 per Attribute decreased, minimum of +1
The character can somehow render victims less able in a given area of the (in)human experience. All rolls involving the Abilities in question receive a penalty equal to the character's Mythos.
Emotional Effect: +1 for Weak, +2 for Moderate, +3 for Strong
The character can somehow inspire emotions in others. A Weak effect influences behavior on a minor level, and can easily be overridden by natural emotions. A Moderate effect is stronger, able to drown out all but the most extreme of human feelings. A Strong effect can induce certain behaviors on its own, and drowns out all natural emotions.
Environmental Damage Immunity: +1 per immunity
The character is effectively immune to one or more environmental hazards, such as fire, electricity, or drowning.
Heals Damage: +1 for Bashing, +2 for Lethal, +3 for Aggravated
The character possesses the ability to heal one or more types of damage. The base damage healed by such a Reflection is equal to the character's Mythos, though depending on the nature of the Reflection, the damage healed might be increased by expenditures of Memory.
Improves Defense: +1 per 2 points of Defense
The character is tougher to hit than the average person.
Improves Initiative: +1 per 2 points of Initiative
The character reacts quicker in combat than the average person.
Improves Multiple-Action/Multitasking: +2
Improves Speed: +1 per factor of speed
The character is faster on foot than an average person.
Instantaneous Transport: +1 for Short-Range, +2 for Medium-Range, +3 for Long-Range, +4 for Unlimited Range
The character possesses some means of instantaneous transport. The charcter travels a number of base units of measurement using a single Action. The precise distance should be set by the Storyteller, keeping in mind the types of travel used in the campaign.
Requires Specific Action: -1 for 1 action, +2 for more than 1 action, +3 for complex dramatic action
The character must perform a specific action to use his or her power. This may be as simple as meeting someone's eyes, or as complex as drawing a complicated geometric figure around something. If the power is triggered by the expenditure of Memory, then performing the action without spending the Memory will have no effect.
Restricted Usage -1 for Common targets, -2 for Uncommon targets, -3 for Rare targets
The Reflection in question may only be used on certain targets, such as plants, other Seeds, unaltered animals, or Archetypes. This attribute may not be combined with Self Only (see below).
Self Only (Evocations Only): -1
The Evocation in question may only be used on the character.
Edit: Edited to reflect the usage of dots, which makes more sense with Storyteller.
Edit: Added explanations of individual Reflection attributes.