Which of these fruits and vegetables are JUICEABLE!?...

Hi,

I'm going onto a major big juice detox soon, getting my list ready of fruits and vegetables I can juice. I'm not too sure though that all the things on my list ARE juiceable..

First of all I'll start with the fruit I'm not too sure about:

Pears
Plums

I remember doing pears before and remember it doesn't always go smoothly. Sometimes I get a juice, sometimes it comes out thicker like a smoothie! Fresh plums were much worse though when I tried for the first time a few weeks ago. When I tried juicing these my juicer got very clogged and after one plum I was just getting a slow, thick consistancy dripping slowly out the juicer. I was really dissappointed by this because I've heard all the benefits of plum/prune juice for the bowel! Anyway, I juicced both the pears and plums with the skins still left on. Could this of been the problem?

Ok, a longer list, all the vegetables I'm not sure if they are juicable:

Tomatoes
Aubergine
Butternut Squash
Courgette
Potatoes
Spring Greens
French Greens
Leeks

Apart from tomatoes, which came out more like a smoothie consistancy (maybe take skin off first), all the other vegetables listed above I have not tried juicing before! If it is possible, how much juice can I expect from things like aubergine, butternut squash, courgettes, potatoes and french beans?

Any answers to any of the vegetables and/or fruit would be much appreciated.