The Learning-A-Language Before a Trip Routine
With only so much time, it becomes a game of priorities.
Prelude:
If you are learning a language for the purpose of travel, if faced with having to choose between learning the spoken language better or the written language better (e.g. with languages that use Chinese characters), opt for the spoken language. This is especially true on tight schedules.
Depending on how much time you have, start with the first item on this list and then go down with the completion of each step.
If an app exists that enables you to learn realistic dialogue, get that now. If a book exists with the same, get it as well. Preferably with any audio output. (Mango Languages, uTalk and many phrasebooks such as Assimil or Kauderwelsch are idea for this purpose).
Prioritize asking for directions and making purchases. Make flashcards of the phrases you’ll need to know.
If you have time, focus on who/what/when/where/why questions, the verb “to be”, “to have” and, most importantly, “to want” and their equivalents.
From there, go through the phrasebook / dialogues until you know every phrase in it very, very well.
If you need practice and don’t have access to native speaker for whatever reason, play conversations in your head. That way, even if you don’t understand what someone is saying to you, your previous “rehearsals” will help you. Keep in mind the “Pingu Principle”, namely that human brains can make sense of spoken based on context even if those spoken words are literal nonsense.
If you still have time, ease yourself into the written language / pronunciation if it is on the harder side. If it is a phonetic language like Finnish, you won’t need much effort on this step.
Prioritize learning new words over grammatical structures if travel is your priority. If you want to sound more polished, venture into the world of grammar occasionally.