well-i am so glad you asked-this is a big passion of mine-the gs if you hadn't already guessed..
well i drink it throughout the day...around 1-2 litres-but my husband drink around 750mls per day,1 glass morning 1 glass evening...listen to your body you will know how much you need..
ingredients well....i think to begin with something a little milder in the greens department...
i have a 1250 blender..
and an average blend would be..
2 big bananas
1 large mango
1/2 bunch of carrot tops(mild tasting and yummm.)
handful of red grapes
800mls to 1 litre of water
and blend blend blend...
you could definitely add your wheatgrass..
and i put a tsp of coconut oil in this blend today...use that occasionally for a different twist to the gs..
have a look on the topic green smoothies with a twist...there's so many recipes on there for gs it will boggle your virgin gs mind...LOL..
whip up a gs,and let me know what you think...the results i am experiencing are miraculous...more on that in the above mentioned topic..

another simple one is-say 4 bananas and as much basil as you want with water-you can adjust water accordingly depending on how thick you like the gs..