English word order and lack of gender differs greatly from the way many other languages are constructed. What might seem a clever use of string fragments in English could be a disaster in French, for example. Sometimes you have to write it twice. If the same English string is used in differing contexts, multiple string resources should be created. Even if the same phrase, in two different contexts, is identical in English, this may not be the case in another language.
Many languages have multiple words where English has only one.
Don't make UI elements positionally dependent. Buttons, entry fields and static text all might have to be reordered to support a different language. If the order of controls matters, you need to provide a way to deal with this in the localized product. If this becomes impossible, a second dialog or a tabbed interface must be implemented. English is perhaps one of the most compact Romance languages.