I like your suggestions in your Translation Fundamentals about using our best friend, Google. I would specify one more trick that is very effective when you don't know how to translate a word. Say, the unknown word is a noun, say a type of handbag, "XXXYYY". If you target is English, you can Google, "XXXYYY [source word for leather]" and "leather". This will very often give you the right answer immediately. Example for FR>EN, if you don't know the best translation for "sac seau", your Google search might be ""sac seau cuir" leather". On the first page, it will seem clear that it's a "bucket bag". But, as many English sites are incorrectly translated, you always want to double check by then Googling "bucket bag". In this case, you will find 2 million hits, including with pictures, from sites based in U.S. countries and your doubts are done.
Another Google trick