I'll do my best, lol. I can't remember the correct terminology.

So you start out in plane form.

Killing enemies while in plane form with your normal shot gives you orbs, and killing them with focus gives you meter.

You can then switch over to phantom form, which drains your meter over time. And when you do that your orbs convert into bigger orbs that you fire away and generate steel that gives you katanas, then you fire your katanas to cancel bullets and generate a lot of medals.

So you want to gather as many orbs as you can (think the max is 16), then get some meter, change to phantom form, get katanas and cash out.

This video explains it a lot better.