How should I approach an unseen Latin translation?

The first, and most crucial thing to do when approaching an unseen Latin translation is to read the english explanation (usually italicised) at the start of the passage. This gives a plot summary and is helpful in orientating yourself with what will happen in the passage. Also, it can be useful to provide a basis for working out any words whose meaning you are unsure of. Then, you should read the whole passage in Latin at least twice; it may be possible to get the gist of the meaning before you start translating. Tackle each sentence individually and, if you encounter a long sentence, divide it by marking in breaks which are indicated by connectives such as 'et'. After translating, you should read what you have written in English to see if it makes sense and accords with the plot summary. Then, work your way back through the Latin checking especially that you have translated verb and noun endings correctly and not missed out any words.