hello friends..... Now i came with a new tutorial i.e on "Creating Custom Brushes".... Here is my small tutoriallet see how it is :)
step 1 :
Open an image i.e what u want.... here i take this butter fly images.

step 2:

now just select the magic tool or lasoo tool and select the part what u want ... here my selection



step 3 :
and i gave the feather = 1 and cut it


step 4 : now open an new document it must be the trasperant mode... and paste the previously cutted image



step 5 : now select the magic tool and select the butterfly.. looks like this

step 6 :
Now go to edit - then define brush preset and name it


Final Step :
Now out making of custom brush is over now try this just select the brush from the brush pallet now draw where u want... i draw
like this

I hope u like this mini tut..... :)