I’ve been playing with some ideas from Dungeons and Dragons. Specifically, the notion of meta-magic. This category includes buffing spells and items that increase the efficacy and power of other spells.
I’ve got at least one project I’m working on already, and have another few that are in the planning stages. I’m not going to reveal all of my secrets here, but I may outlines some of my successes or failures. (Probably more failures. I’ll want to keep the successes to myself! But the failures everyone can benefit from, I suppose.)
I’m interested if anyone else has experimented with this type of magic before. Since I’m not planning on sharing all of my work, I won’t ask the same of others, but just a general acknowledgement of this line of thought would be appreciated.
Blacklight Metaphysics 
I’m not sure if this is quite the same as your meta-magic, but I use a form of sympathetic magic utilizing, say, pink and black sand from Andrew Molera State Park if I want a boost of “sea energy” to certain spell work but can’t actually get to the ocean. It’s as if I were tapping for mana (another game entirely) to cast that spell.
What I mean by “meta magic” is magic performed to increase the power of other magic. A talisman that amplifies the power of a cast spell, for example.
The “real” spell is to bless the home just prior to a wedding. The meta-magic spell could include preparing five rune talismans with beorc, one a month for the five full moons before the wedding. Then for the “real” spell place those talismans around the home/property so that if you were to connect the dots, so to speak, from a bird’s eye view it would reveal the beorc rune. I’ve always considered that process a layering of magics because of the time commitment and forethought, so maybe that’s what you’re asking.
No, I think you’re missing it. Say you cast a spell to get a new job. Then you cast a spell to make your job spell more effective. That’s meta-magic.
You find a job posting, cast a spell, apply for job. Following week a Aries full moon falls on a Wednesday night so you power up your previous spell with another, astrological-based spell. If that’s not where you’re going, I give up. =P The idea of boosting a previously cast spell is intriguing, but assumes that one’s magic is weak to begin with. Of course, that can happen if a spell needs to be cast in a hurry.
As I understand it, it’s better to spend extra time beforehand making the spell as complete as possible and then letting go, rather than returning to a previously cast spell in an attempt to plug in the holes of an incomplete casting. Sometimes, some things are just not meant to be. Meta-magic sounds very mechanical, like enhancing a car engine, which is not surprising since it stems from a game. I have a hard time imagining where going back to save a spell might prove successful, but I wish you luck on your experiments is this field.
No, you’re getting it. But how I’m using it is more proactive, like saving up a charge for a spell you need to cast on the fly. It really just comes down to generating the energy for a spell over a long time instead of all at once when you cast it.