Check whether the document to be translated is available in an editable format (image and PDF files are not editable). This will make the translation process easier, and you will save extra costs for file conversion etc. It also ensures that the translation has the same layout and formatting as the original.
The document should be finalised before sending it for translation. That way you avoid unnecessary and expensive extra work. Major changes to the document can also make it difficult to meet the agreed delivery deadline.
It is a good idea to appoint a contact person with sound knowledge of the field involved who can answer any questions the translator may have during work on the translation.
Put quality first. It pays to choose quality-assured translations carried out by skilled translators.