I spoke in e-prime for a summer a couple years back. It challenged me a lot, and I came to a couple conclusions. If you've ever travelled to a foreign country to try out your language skills there, you basically will undergo the same experience using e-prime here. It helps to imagine yourself as a foreign visitor who has to translate "english" into your own logical system, much like when a hindu guy says things like "I am being one who is being very pickled at you!". People who speak english as a second language often try to adapt english to their native language's conceptual system.
In fact, I ran across a story, by Dr. David Bourland I think (an original e-prime user), where he tells an anecdote of a woman asking him "Where do you come from? You have such an interesting accent!". He had no accent at all, except his absolute neglect of the verb to-be. People will adapt their ears to you, and come up with their own fascinating explanations.
You have to abandon A LOT of slang and colloquialisms. No more "whassappenin'?", no more "what's your sign?", you'll just have to reinvent ways to ask people how their lives have gone recently, and what their parents named them (instead of "what's your name?").
You'll need to religiously stick to active tense. You'll restart sentences a lot when you find you've started it in passive-voice construction.
Saying things like, "the problem with such-and-such is...", "what I like about such-and-such is...", "the thing is..." goes right out the window. Instead, you'll say, "I see a problem about such and such, in that...", "I like this about such-and-such", etc. I laugh at [almost said "it's funny"...] how well the previous examples illustrate the remarkable advantages of e-prime! Statements of what you observe, of action, of things doing things, will have to dominate your spoken e-prime.
This actually excites me to want to speak in e-prime! I had a lot of fun that e-prime summer, not so long ago. Enjoy the hassle! Grin at the perversity! Notice how much people flap their lips, and say nothing! Convert arguments into e-prime observations, and watch the arguments dissolve!
Please tell me if this has helped. I've thought about starting an "e-prime sandbox" here, where I (and others!) converse, including all my edits to show where "to-be" tempted me, and I had to find a way around it. Even this message featured three or so situations where i had to rethink a sentence. In spoken english, I love saying "The funny thing is...". Why do I say that? What does that mean? I'll have to think about a better way to express my own amusement.