Tips for extending battery life

[Omid]

I have a Xperia Z.

As you know,the battery is irreplaceable.
Tips for extending the battery life?
Which activities damage the battery and should not be done?
For example,when(battery percent) should we charge the phone?Should it be completely discharged or not?
Is it harmful for the battery to be plugged in while it is fully charged(for example,when the phone is charging over night)
tnx

[Nabeel]

It's always good to check out the FAQ's

Here you go 

 http://talk.sonymobile.com/t5/FAQ/Battery-time-and-enhancements-features/m-p/347874#U347874

You can also check the tips given in user guide

http://userguide.sonymobile.com/referrer.php?region=global-en&product=xperia-z#!Battery.html

http://www.sonymobile.com/global-en/support/faq/xperia-z/troubleshooting/my-battery-runs-flat-too-fa...