Mostly I have been using carrots, beets, cukes, watermelon, apples, grapes. I haven't done much with greens (more about that below).
I made a delicious juice today from tomatoes and red peppers, cuke, a clove of garlic and some onion. Then I added a dash of olive oil. I was trying to make a "juice" version of gazpacho. It was yummy!
Later, I bought some kale. I have done much green juice and thought it would be good for me. So I juiced up the kale with a raw potato a clove of garlic and a bit of onion, and it was NASTY but I drank it anyway.
I am in my 6th day and having trouble with hunger for the first time since I started, but I am handling that by having small frequent servings of juice, lots of water, and leaving the house for a walk when necessary.
When you say you can't have sugar, I guess that would include freshly juiced fruit? That's too bad. What about carrots? They are the backbone of many a juice-fast, I understand.