My typical blend (a tall glass each for 2 people) is 4-5 kale leaves and stalks, 4 celery stalks, 1 cucumber, 1 lemon, 1 orange, 2 apples, 1 handful of parsley, 1 inch of ginger.
I will often mix in 2-3 carrots instead of the orange. Really depends on what looks good at the market and what you have on hand. The ginger gives it a nice peppery bite. And either peel the lemon and orange before juicing or juice separately, the juice will be very bitter if you don't.
The hardest part is the cleanup. I bury the leavings in my garden, rinse the parts, scrub the element a bit and put the whole lot in the dish washer. Kind of a pain but the results are well worth it.
Good luck and keep us posted!