Run windows in power saving or energy saving mode
It'll keep the display dimmer
Put the computer to sleep faster
Shut off the monitor faster
The processor will be able to down clock itself as long as you don't have a manual voltage on an over clock, if it does have manual voltage the CPU my down clock but the power consumption will stay the same
Other then that any 3rd party type software I personally wouldn't really trust as it would have to be able to control your processes, meaning it can turn whatever it feels like off and your nine the wiser about what just got switched off
Computers actually don't typically use that much power, refrigerator and a/c probly use more power then your PC on a day to day, just because it has 1000w PSU doesn't mean it pulls that all day
CoolerMaster HAF 932 Advanced/ Maximus VI Formula/ I7-4770K/Swiftech H320/ Corsair HX850/ G.Skill Trident X (2x8) 16gb 2400MHz/ 2x 840 EVO 120gb(Raid 0)/ WD 1TB HDD (Backup/Storage)/ EVGA GTX 1gb 560 TI/ Asus 12x bluray combo