I find Langenscheidt’s language courses really good. They are pretty straight forward. If looking for a teacher isn’t an option, I would go for those books + assimil till i master some basics and then I would jump on something that i really enjoy. Books, series, whatever.

If getting a teacher is actually on the table, I would look for someone that is eager to teach me only using the target language.

What is your target language and your mother tongue? Sometimes, language similarities help easing the way.