GARDEN SOIL VS POTTING SOIL

I am not exactly sure what the difference between potting soil and garden soil.

I know that garden soil is susceptible to impacting more and it is sterile.
Whereas, potting soil has perlite and more peatmoss and it is sterile; and less able to compact after waterings.

Well this leads to this question..

Can i just add soil and perlite to garden soil and use it as a potting soil?
and i am thinking of adding some lime to adjust the pH and have some micro nutrients for the soil mix. how much lime should i add for 1 cf of soil? How much sand and perlite should i add for the right amount of texture?
I should probably measure the pH first.

How can you tell if it's has the right texture after adding in the sand and perlite? I heard of some kind of finger test but i'm not exactly sure how that works out.

I will be using this soil strictly for potting plants only.

For texture you just grab an handfull and sqeeze it. It should compact a little but it should crumble easily when released. A good quality potting soil usually has more of the micro nutrients need to start seedlings.