well you have to get down on your knees, some like to squat, but I just fall over when I try to do that..
then you make a circle in the dirt with a stick, like this....

the marbles go in the middle of the circle, but make sure not to put anything in there your not ready to loose if your playing keepsies...I use my lucky marble..
I take my finger (thumb) and place my lucky marble in front of it, there's a certain way to hold it in your hand, almost like a fist, you hold your hand like this a little above the line
But it can't go in the circle, cause then that is fudgies, the goal is to knock the marbles in the middle outside of the circle, any that go outside the circle you gets to keep if playing for keeps, if not then its just for fun and practice..
I find it helps if my tongue sticks out of the corner of my mouth just a lttle and I close one eye, dont know why..but it helps my aim..oh..and would not recommend playing it in a dress with boys around..otherwise you hear giggles and can distract you(s)...