The accomplished translator can develop good as well as bad habits. 

BAD HABITS:

1. to lose touch with the source language for long periods of time.
2. Taking illegitimate shortcuts while translating, like falling to look up a word one is really not sure how to translate. 
3. To summarize a paragraph instead of providing a full translation. 
4. The worst habit for a translator is to decide at a certain point in time that his or her knowledge of either the source or the target language is so good that it cannot possibly stand any improvement.  The moment one stops growing linguistically, one is no longer on the cutting edge of one´s profession.  The good translator is a perennial language student, always eager and willing to learn more and to keep up with the latest.

GOOD HABITS:

1. one excellent habit is to read professional literature in the field one will be called upon to translate in with reasonable frequency.  One good example is Scientific American, which can help anyone who translates subjects of science and technology.  And people who work in the field of translating business documents should definitely read business periodicals, The Wall Street Journal, the Times, American Business magazines, articles, etc.
2. to be always on the lookout for dictionaries.  Many dictionaries are hard to find, and are available in few places. 
3. The practice of compiling word lists and building a reference library.  Dictionaries do not have all the words and terms a translator needs, nor do they contain all the information which specialized references may have.  There are aids for translators put out by certain organizations, and there is professional literature in every field.  Good references are worth their weight in gold when they are needed for a specific translator.
4. To consult experts on the specific subject we are translating.
5. To re-read again the original and the target text and to take into account to which audience we are translating for.

Can you think of some more good and bad habits?