Set Bluetooth to Off. Also, if you don't plan on using the WiFi turn it Off too.
Go to Settings -> Privacy -> Location Services
Turn Off all the apps that don't need to know your location. Continue to System Services...
Turn Off Location-Based iAds and any other setting that you don't want to use. The less your iPhone uses the GPS, the better your battery life will be.
Set Siri to Off
Set Brigthness to the lowest setting possible. IOS 7 is bright enough :-) Set a static wallpaper instead of a dynamic one.
Set Reduce Motion to On (disables the Parallax effect)
Set LED Flash for alerts to Off
Settings -> General -> About -> Set "Diagnostics & User Data" to "Don't Send"
Set Background App refresh to Off
Settings > Privacy > AdvertisingSet Limit Ad Tracking to On
Set Fetch New Data to Off
Set Use Cellular Data to Off