How to help my battery last?

I have an iPhone 5s, and all of the sudden my battery is dropping twice as fast as it normally does and i'm still using it the same as before, i'm closing out my apps, what else can I do to keep my battery lasting long?

There's a low power mode on newer versions of iOS go to settings, battery, and turn low power mode on. Remember that your phone will turn this off automatically at 85% battery, but you could just turn it back on manually. You could also go to assessability and turn reduced motion on. This will turn off the transitions but, won't affect the performance of the phone. You could also stop the phone from fetching E-mail automatically every hour. Go to mail, and turn fetch new data off.

Do all that zachary jay says, but also don't be quick to recharge your phone. Let your phone die at least once a week, like all night dead. And also let your battery go way down before recharging, and when your phone is 100% recharged take it off it's charger. It'll "train" your battery.

Also having internet always on your phone drains the battery, turn it off when you don't need it.