I got a juice processer for my birthday (Dec. 29th) and I swear to God I´ve used it every day since. The trick is to always have good stuff at home, so I always stock up on some or all of these items: carrots, cucumber, apple, red beeets, parsnip, celery, lemons and ginger. A good thing about these ingredients are that they´ll keep for a long time in the fridge if you don´t end up using them right away.
I have such a sweet tooth and roam the house for leftover sweets or snacks several times a day. But this usually helps me.
It´s delicious and makes a very pretty mess in the kitchen.
My favourite is parsnip+red beet+lemon+ginger, while the kids prefer apple+ginger.