Shoot the Bullet/Gameplay/Strategy
Keeping the Camera Charged
Always remember that your camera must be charged to a full 100% before you can take a picture. Most of your time spent during any battle in this game will be spent dodging bullets; of course, any Touhou player knows you should dodge bullets to avoid death, but in this game, you'll find yourself dodging bullets more and more for the express purpose of finding an open safe spot - even temporarily - that you can use to snap a photo.
Be sure to know and use all three levels of speed available to you: normal movement for quick dodging, Focus when there's slower, precision dodging to do, and Focus and Shoot (Charge) for charging quickly.
With the camera fully-charged at 100%, you're likely anxious to snap a photo. However, just taking any old picture isn't going to please Aya. The bare minimum that she requires to deem a shot a Success is that the boss must be present somewhere in the picture. Generally, this requires being somewhere near the boss yourself, which almost always means you're going to be in danger when you attempt to take a photo.
Thus, waiting for the right moment to take your photo can be crucial for a multitude of reasons. One strategy is to take a shot the moment the boss has finished unleashing their latest barrage of bullets (both for color bonuses and so you can clear them off the screen). Other situations occur as well, with some bosses being decidedly camera-shy (like Youmu or Reisen), and you must wait for them to become visible and/or charge at you to take a photo (even if you know where they're at, taking a picture of a temporarily invisible boss will be a Failed shot: Aya wants to be able to see the boss in the photo).
Of course, just having the boss in the photo would be boring, and thus Aya will award you bonuses for any aesthetics in your picture (anything that just plain makes the photo look good).
A list of bonuses can be found under Scoring.
It also helps to get lots of bullets in your pic, not only to help charge your camera after the shot, but also to go for color bonuses. If you get enough bullets of any given color in your shot, it will give you, for example, a "Yellow Shot" bonus for lots of yellow bullets (or if you get a large variation of colored bullets in your shot, you could even get the "Colorful Shot" or "Rainbow Shot" bonuses).
If you're close to bullets yourself when you took the picture, you'll get a "Risk Shot" bonus. How big that is depends on exactly how close you are to the bullet(s), and how big they were (this includes lasers).
It's not always possible to get tons of bonus designations on every shot, but getting them when you can will certainly help inflate your score.
There are times you'll get yourself into a situation you simply cannot get out of. And since Aya is not carrying any bombs, you might ask yourself, what can she do?
Take a defensive photo.
You must remember two things about taking photos of bullets: One, any bullets caught in your viewfinder when you snap a photo are cleared from the screen, and two, any bullets captured in a Failed shot count double toward recharging your camera.
So when you find yourself in an inescapable situation, hold Shoot long enough to outline an area of bullets you want to clear, then release it to get rid of them.
Aya will deem your photo a Failure, of course, but you're no longer in dire straits, and if you captured enough bullets in your photo, then you're already more than halfway toward a 100% charge again.
This is a list of tactics for defeating each Spell Card in the game. This list is not exhaustive; in addition, many cards are simple "skill cards" with no particular strategy required. Please note that the contents of this list could be considered spoilers.
Spell Card Strategy
The list is cross-referenced with Spell Cards.
Many replays of successful completions of the spell cards can be found here for viewing-