in ground soil preparation...

hey all. just wandering, I know there are a million recipes for a healthy soil, which i have searched and explored so far. but they all seem very involved with mixing, measuring etc. i want some thing that is easy to make, but still has the necessary nutrients. I dont know if i should use actual garden soil (for inground) if I am planting in the ground, or should I only use potting soil for container. the potting soil looks like it has more nutrients that then plain garden soil..? What can i mix with the bagged soil (either the garden or potting soil) to get a good source of nutrients going. or do I not need any, except of course for the usual growth fertilizers. Should I add bonemeal, peatmoss, perlite, worn castings, etc.? I dont want to have to measure a million items and determine quantities to add some nutrients,I just want to use a nutrient(one or two) that can be added by simply adding some to the soil/hole and mixing in, not having to be exactly percise w/ the measurements, u know what i mean? I was thinking maybe some bonemeal and perlite, but im not sure. Thanks alot for ur help fellas.