Overclocking your PC's GPU to get max performance!

We all want to get more performance out of our Computers for gaming but many times our computers disappoint us. So i hope to teach you the basics of overclocking your Graphics Processing Unit (GPU) to get more power for free! But let me clarify first that overclocking can also be extremely dangerous to your hardware if you don’t know what you're doing.
I tried over clocking on my laptop, even though people prefer to overclock their desktops. I did the temporary software based overclocking instead of messing with the BIOS or the hardware itself. I have a Nvidia GT 425M graphics card whose shader clock runs at 1120MHz and core runs at 560MHz and its memory frequency is 800MHz by default. I managed to get 180MHz more of shader clock frequency with ease. I still think I can increase these a lot but I want to be on the safer side. I have seen that a person has increased an identical laptop's shader speed to 1460MHz , core speed to 730MHz and memory clock to 900MHz.
I used a software called NVIDIA inspector even though you can use other softwares like ATI Tool and RivaTuner  . I will focus only on Nvidia inspector here as it seems to be the simplest for Nvidia Cards.
 Nvidia inspector doesn't even need to be installed, its a simple .exe file. When you run it click the Show Overclocking Button it shows a warning then you get a few sliders to work with. So when you are trying to overclock, first work on either the core clock or the memory clock. Not both simultaneously. Increase the clock speed of shader or memory in short increments of 10MHz-20MHz.  Keep slowly increasing the clock speed until you see some artifacts on your screen. Here artifacts means some lines, dots, grouped pixels, statics or anything unusual on the screen. When you see the artifacts reduce the speed by about 20-30MHz. Then stress test your GPU by playing some heavy game or running some 3D test. If everything is good then too then this speed would be the maximum clock speed of your shader or memory. All the while you do it make sure that your GPU does not over heat, monitor it constantly. The temperature of the card should not hit 90 degree Celsius.
Once you have found out your GPU's maximum speed save it by creating a shortcut. These settings do not load when you boot your PC so you will have to run this shortcut every time before you play a game.
Using default settings for my GPU i could get 22-24 frames per second at resolution of 1280x720 in Battlefield Bad Company 2 but after overclocking the frames per second jumped to 30-32 in a resolution of 1366x768! That's a lot of performance increase.
If you want to achieve even higher overclocking then buy some better cooling system for your PC or    BUY A NEW GRAPHICS CARD! :D