When I first started simultaneous interpreting for the US Department of State in 1974, I observed that sometimes I did not readily find the necessary word and I asked myself: "How does one say this in English?" I was short of words, and this was a serious shortage. This shortage was accompanied by a certain excess: when I was going from the original to the translated sentence, superfluous debris of unprocessed original(s) often ended up carried 'across the immune boundary' into the body of the new organism, the translated sentence. This was not desirable. Each of these organisms (the original and the translation) is clean within itself and for itself, but they ought not to be contaminated by each other's 'bodily fluids'. It can lead to such 'diseases' as impoverished vocabulary, alien sentence structure and word order, irrelevant cultural assumptions, use of idioms non-existent in the target language, tortured syntax, and, finally, sentences which are difficult or impossible to understand.
I asked myself:
"Why am I talking like this in the target language?" and my inner voice answered:
"Because you are not talking in it."
"And what am I doing in it?" I asked.
"You are copying, you are imitating the original."
Then I thought:
"Oh, my God, I better stop doing that and begin to talk."
Between talking and interpreting there is at least one important difference. Talking happens from a place inside of me to the resulting sentence which is outside, while imitation happens from the original sentence outside of me to the final sentence which is also outside. Thus in the imitation process I play only the motive role of the means of transportation, but I do not generate the cargo in any way. I am just the train that carries sentences from point O (the original) to point T (the translation). What I decided to do instead, back then in 1974, and what I still practice today, a quarter of a century later, is three-point translation.
I listen to the original and interiorize it. This causes a certain feeling inside, like the lump I feel when I want to say something of my own. Then, without looking at the original I say it, or I verbalize this lump, just the way it happens when I speak in the target language or in any language, for that matter. The sentence I say sounds natural and clear; none of the debris of the original muddies its clear form. While saying it, I compare it to the original ever so lightly, just for compliance control.
This description sounds complicated, but so would a similarly technical description of the way you walk. In reality, all this is fairly easy to do. Just don't be in a hurry to carry the original to the translation. Interiorize it first and get a feel for it, then forget about it and where it came from, and speak. In addition to making the interpreter sound natural and opening access to the enormous natural vocabulary one possesses without being aware of it, this three-point process keeps one alert and helps against being hypnotized by the original.