I made some fresh carrot juice yesterday, mmm
Here's what I would suggest for a couple big glass's:
10 carrots
2 apples
1 orange
1 grapefruit (optional, I found the grapefruit made it pretty sour and bitter)
I used my juicer instead of my Vitamix, but you can use the Vitamix and strain the juice through cheese cloth or a strainer bag.