Make a simple key logger, then count the number of times each key is pressed. Run it for a day or two, then save the output to a text file. Do this every once and a while. It doesn't matter what layout you are using, as you are just seeing which keys are being used the most.
If you want to make a good layout, you can't be afraid to go away from the norm. I'd suggest putting the top 11 keys along the home row, then the next top 11 keys as the top row (leave the 2 keys above the return key as the least used keys), then the 3rd top 11 keys as the bottom row. There should be 4 keys left over now. Take those and put them in the -= and ]\ slots. Congrats! You have now made a great keyboard layout for your purposes! =D
