How to tell when PID's are properly set?

[N7KI]

I';ve been through many batteries trying to tune the PID';s on my DJI frame quadcopter.  I thing its seems to be flying ok sometimes during a flight and will set there and hover for a few seconds and then goes off.  Sometimes it goes high without throttle input.  Any hints/help will be appreciated.

[firey1]

what flight control board  and program are you using

[N7KI]

I';m using the Crius AOIP V1 board with the Multiwii 2.2 Software. 

[firey1]

 i use mega pirate but
but what i have found if it climbs i put foam over the baro as its sensitive to light and prop wash creating unstable hover

someone else maybe able to help with the hover as with gps and mega my hover/loiter is rock solid to within a 300 mm  or so of wander

as far as pids this vid explains well  based on a kk board but explanations the same

Multicopter PI-tuning: How to recognize different settings.

[N7KI]

Does string tuning work ok with x frame quad? 

[fruitsalad]

have a watch of this
principles are the same..
i used this method on my multiwii v2.2 tuning..

CRIUS AIOP V1.1 Project Part 16 - PID Tuning For ACRO Mode