Dim all the lights. This includes dimming both the screen and keyboard lights. The function keys on the keyboard are the best place to adjust the brightness of both. Keep the display on a setting as low as you can tolerate and turn the keyboard backlight off entirely if you can. In the System Preferences for the Display be sure that you do not allow your Mac to automatically adjust brightness. This goes for the Keyboard preferences too: there is no point in having your Mac adjust the keyboard brightness in low light if you intend on keeping it turned off in the first place.
Turn off the screen saver. After setting the Energy Saver back to the default settings, the screen will be turning itself off after just two minutes. And since there is no screen saver on the Mac that consumes little to no energy, just turn the screen saver off entirely. To do that, you need to set the Start After property to “never.” This is located on the Screen Saver tab within the System Preferences for Desktop and Screen Saver.
Get rid of Adobe Flash - If you do not feel you need Flash, then do not install it in the first place. If you have it, unfortunately Adobe does not have a convenient kill switch for Flash in such situations. But there are apps like FlashFrozen ($0.99, Mac) and FlashBlock ($0.99, Mac), which are both available in the Mac App Store. Either of these will turn off Flash and allow you to browse the internet Flash-free.
Stop sharing services. Only turn on what you need to have on. From within the System Preferences open your Sharing settings, and see if there are any that are turned on that you no longer need. Especially when you are out and about on public networks, there is no good reason to leave on your sharing services. Your best energy-saving option is to have them all off by default.
Block incoming connections. It’s also a good idea to block all incoming connections. This will prevent applications from waking up and performing work in the background and using precious battery. This includes applications like iTunes, Dropbox, Messages, FaceTime and even Skype from receiving an incoming connection. These apps will be able to make an outbound connections just fine, so this setting will not render the apps completely useless.
Disconnect from the network. If you don’t need to be connected to the internet, be sure to turn off your Wi-Fi radio. It is actually a good idea to create a network “Location” that basically connects to nothing at all. From within System Preferences, select Network. Create a new Location by first Editing Locations and clicking on the “+” to add a new location. Label this location “Disconnected” and click Done. Make sure that your location is set to the newly created “Disconnected” and start removing the default services that were assigned until no services exist. Once you have removed all network services from the location, click Apply. This will keep your Mac from connecting to the network entirely.
Turn Off Bluetooth. First, if you are one who carries around a Bluetooth mouse or — heaven forbid — a Bluetooth keyboard, just stop. And get used to using what is already attached. But if you only use them when you are at a desk with a power adapter attached, then be sure to turn off your Bluetooth radio when you are out and about. There’s no reason to leave it on if there is nothing to connect to.