Learning and understanding the minute grammatical and syntax differences between languages will help translators avoid simple spelling & grammar errors. Additionally, avoiding literal translations will help preserve the integrity of the work.
Reading books, listening to audio files, perusing grammar books and even observing body language will help translators understand what words and sentences mean. This will help translators get a better picture about the way language is used in a particular country and it will help reduce errors due to mistranslation and misuse of words.
Proper proofing
Reading and re-reading the material will help translators spot mistakes in spelling & grammar and identify any inconsistency in the translation. Translators should also add end-notes post-translation to help readers understand what a word means or why it has been used. This will improve overall quality.
Quality tools such as spellchecker and CAT tools can help identify errors at a much faster rate. These tools will help translators identify which parts of the translated piece are below the level of acceptance. Additionally, having a dedicated team of quality assurance professionals will help ensure there is a four-eye check of the final translated material.