Step 1: Materials
You will need a power inverter. I got mine as a present so I don't know what it cost. luckily it had pop out plugs because I could not find cool ones at the hardware store. It also had a 5 volt usb plug which I thought would be cool to use.
All vehicles are different but you will need tools to get behind the dashboard plus whatever you are mounting the plugs to.
You will need wire and connectors to attach to the battery and the from the hidden inverter to the plugs. Be sure to use appropriate gauges for what current load you are expecting.
You will also need some inline fuses and a 12 volt extension plug. The one I got had two outlets side by side.
I used a drill, an angle grinder, a jigsaw some sandpaper and some files.
2 small bolts and nuts to mount the panel.
Step 2: Location and design
I wanted the plugs to be accessible but not obtrusive. I chose the floor console right below the drink holders. this may be a bad idea for people who use the drink holders a lot because you could spill liquid into the plugs causing a short. I don't use them much so this is where I chose to put my panel.
Once you are firm on a location, you need to design the layout and shape of your panel. I used a program called solidworks to do this but the freely available google sketchup will work fine.
Step 3: Transfering the template
Step 4: Shaping the panel
Step 5: Ripping apart the inverter
Step 6: Wiring to the battery and hiding the inverter
Step 7: 12 volt plugs
Step 8: Power switch and 5 volt usb plugs
There were also leds by the button and I left them buried. To be honest, everything I plug into it has some sort of led to tell me if it is powered up anyways. I don't need more leds in my truck.
Step 9: 120 volt plugs
Step 10: Assembly
Put the dash back together last after it has been tested.