A lot of odd behavior can be attributed to an incorrectly setup throttle range. Setting up the range of your throttle will go a long way towards eliminating these kinds of problems.
1. Download and install the Hoverfly Setup client.
2. Attach the USB cable to your flight controller and click Connect button on the General tab of the setup client
3. Turn your radio on
4. With the propellers removed from your motors, connect power to your flight controller
5. Set your throttle stick to its lowest position
6. Adjust the end points on your radio's throttle channel so that the throttle slider is at its lowest setting when your throttle stick is at its lowest setting.
7. If the throttle endpoint has been set too high, the throttle slider in the setup client will show as centered.
This does not affect the throttle when flying.
8. Repeat 5 and 6 with the throttle stick on your radio set to its highest setting
9. Calibrate your ESCs using the Throttle Range calibration specified in the manual of your speed controllers
Skip this step for Castle Creations and similar ESCs.
10. Test the changes you made.
The ESCs on your multirotor should start your motors within 10% of the lowest throttle setting.