Make a schedule. The steps that follow are a five to seven day program, starting with grammar, moving onto to phrases, and finally vocabulary. You might have a different preference or the language you're trying to learn might dictate something a bit different.
Master the basic verbs first: to have, to be, to want, to need, to do, to go, to see, to think, to work to give, to take and to buy. These are usually irregular, so you'll need to know them well. Memorize them in the past, present and future tenses, but don't worry about other ones. In French, for example, the most common past construction in speech is "avoir" plus the past participle and a very common future construction is "aller" plus the infinite. You can find verb charts on the most common tenses used in speech in the Oxford Dictionary and Grammar books.
Memorize question words and numbers. You're only getting a basis in the language, and the best way to form a foundation for learning is to know how to ask questions. The most common question you'll probably be using is about buying and directions, so learn how to ask how much something is and understand the answer.
Memorize indirect pronouns (I gave "him" the book), prepositions (to, by, with) and conjunctions (and, but, or). Try to start making simple sentences, like, "I want to go to the movies," or "Give me my money, please," or, "I think it's five o'clock." Don't worry about getting things wrong, just memorize the words and sleep on them.
Start to memorize phrases. This is where your phrase book comes in handy. If you just pick it up and start trying to learn the phrases, it will mostly be meaningless letters or sounds, but by beginning to get some sense for the grammar and structure of a language, you'll be giving yourself a better basis for learning more later.
Repeat your pronunciation by following a recording. You might actually know exactly how to spell the entire sentence you want to say, but unless your pronunciation is quite exact, no one will understand you. Spend a lot of time just repeating a few phrases, and the rest of your pronunciation will fall into place. Songs can be good for this.
Learn as much vocabulary as you have time for. Now is the time to dive into adjectives and nouns. Make index cards, put stickers on the things around your house, make lists, whatever works for you. The best way to learn words is by interacting with things they represent.
