I will tell you that all of this information is based off of 2 years of experience, and some C/Objective-C knowledge.

///Please backup///
///Don't do too many file mods///

Some myths that need to be busted:
- Removing LaunchDaemons is both dangerous and ineffective
- Language packs do not slow down the opening of most apps
- Removing the @2x images on older devices only frees up disk space.

What you should NOT do:
- Any of the previously mentioned myths
- Delete necessary files

What you SHOULD do:
- Delete unused/unwanted app store apps. Look for the key in their Info.plist: "UIBackgroundingModes" and the string "Continuous". These apps are usually the ones to delete. This includes: Most Battery/ system apps, voip apps, and messaging apps.

- Disable .dylibs. Any .dylib or "Extension" is a RAM hog. Disable
- PreferenceLoader
- libhide
- Backgrounder (This one is HORRIBLE)
- Winterboard (Again, horrible)
- Anything that hooks more than 3 things
- Anything that hooks springboard, AND is more than 200KB
- Anything in it's first version
- Anything that you never use
- Anything that does not do something useful

Disable .dylibs: libhide.dylib -> libhide.dylib.bak AND libhide.plist -> libhide.plist.bak

-Reboot frequently
- Avoid adding capabilities to springboard
- If you have added to the capabilities, then remove capabilities from springboard:
- international-settings
- accessibility
- anything you don't need

Don't do anything dumb