You can use powertop (
sudo powertop) to see your biggest energy consumers, and to check (under "Tunables") if laptop-mode-tools/TLP are working properly - most parameters are supposed to switch to "Good" once the laptop is unplugged.
Some minor parameters (like VM writeback timeout, swappiness etc.) which are not auto-adjusted can be adjusted manually. Google will help you to find out how.
However, if your laptop has AMD/Nvidia graphics, power drainage is probably caused by the opensource X graphic driver. In which case, as much as we all like opensource, you have no option but to install proprietary video drivers (fglrx/bumblebee respectively). You will easily find the how-to's on the web.