I have aslways had an issue with my new phones, the battery life s always so much less compared to the specification set out by the manufacture. So I need to know, "do i charge my phone before i use it or use it untill the battery dies then charge it"?

Before you use it the first time you SHOULD leave it on the charger overnight to get a FULL initial charge.

I usually wait until its low before recharging. That way you keep the battery conditioned for best use. If you keep charging it with a high level of charge you stand the chance of ruining the battery and shorting its life.

You always need to charge before first time use it.

For a longer battery life you should recharge phone when it have 15-10% battery level.
And you should charge it full in once for better battery life.
If you have Samsung galaxy smartphone You can follow tips here (http://www.nkjskj.com/android/tips-to-extend-battery-backup-of-samsung-galaxy-note/)

Ive found depends on the phone, some you actually aren't suppose to charge first until they drain

Ive found depends on the phone, some you actually aren't suppose to charge first until they drain

I'd argue against that speaking as an Electronic engineer.. who has actually seen the difference the first few charge discharge cycles make to the actual capacity and life of a batttery pack. Starting with a full charge... and a running it down to a level when the phone shuts itself down (meaning low but NOT completely dead) for the first 3 or four cycles actually gives the best battery capacity with the longest discharge cycle... and by significant measurable levels. And yes those do vary from battery to battery as far as exactly how much. But it can amount to hours of talk time per recharge cycle in some... many minutes extra at the least.

But then... take into consideration... who has a financial interest in selling a new battery and/or a new phone down the road. Multiply that by hundreds of thousands or millions out there... its not an insignificant profit center.