This mixture is similar to the mixture Mel mentions in his Square Foot Gardening book.   I'm not sure this has the desired nutrient ratio.  I may adjust the mixture later.  These compontents were purchased at WalMart.  Notice, I am not promoting WalMart or a particular manufacture. 

I mixed the parts mentioned below in a 3 pound butter tub with a lid.  This tub will hold one batch of fertilizer and I can put the lid on to store the mixture.  I use one trowel full of component for 1 part of mixture.  I include some organic peat in the mixture to add organic material to the soil.  Mel recommends leaf mold (compost), but I don't have any this year so I used organic peat.