When thinking about learning a new language, it's common to think about it in terms of "what's the word for this" and "how do I say that", as if all that differentiated one language from another was the words they use to say things. This is a very common fallacy. It's also wrong.
In reality, there's much more involved. It's not just knowing the words, but also knowing how they are pronounced. How they sound. How they are combined. Grammar. Usage. Implications. Subtleties.
There are many aspects of a language that stem from a different thought, the level of thought is where translation has to happen in order to reach fluency.
Learn to think differently
Let's talk about how the brain works. We learn by creating pathways. The first time you do a thing, your brain connects a pathway, and each time you repeat that thing, the pathway is strengthened.
The first thing worth noting is that repeatedly doing something wrong will strengthen a bad habit. The second thing worth noting is that because we're dealing with pathways, shorter is better.
Memorizing words doesn't work, because you're connecting sounds in patterns. When you learn by memorization (eg, in German: car, Das Auto, car, Das Auto, car, Das Auto), the series of action inside your brain is complex:
First, you learn a new word, most commonly by hearing it's sound. For instance, Das Auto.
Next, you hear which English word it means. car
Because you only know the English word, your first connection ties the English word to the new foreign word. Das Auto means "car"
Only then, do you create a (weak!) connection back to the word you just learned. car is Das Auto
After much repetition, your brain has now connected the sound of one word to the sound of another.
This last part is the most important detail to remember: You haven't learned how to describe a car in German, you've learned how to connect a series of sounds in English to a series of sounds in German. That's really bad! Why? Because now, when you want to describe a car in German, your thought process will necessarily involve your mind replaying the audio of the word car, in order to connect to the German equivalent.
But this isn't how you think in English! Describing things in English doesn't involve connectings sounds first. In your native language, you have connected the very concept of a car to the word "car". The physical pathway inside of your actual brain is shorter and has fewer steps.
Learn your new language just like your native language
See an image of a car and learn the words Das Auto. Don't participate in any rote memorization, like the Pimsleur Method and Byki. No matter how innovative their methods of helping you remember things, these programs are fundamentally flawed because they are based on bad assumptions about the human mind. Memorization programs can teach you a lot of words, but they will leave you frutstrated and useless in an actual conversation.
If you think it's hard to take three steps from "car" to "Das Auto", imagine how much more work it will be when you are taking three mental steps for every word in every sentence? Your speech will be painful and slow. But even more painful, you'll have to do that same three-step mental process to convert everything you hear back to English! This is unmanagable!
For this reason, it is essential that you connect a thought with a word — the same thing you do now in English. For things, pictures work well. For feelings, use your imagination. For verbs, you need to truly visualize the action when you hear the word. Connect every new word directly to a thought, and strengthen this short pathway in your brain tissue by repetition.
This is one of the most important things you will ever learn about language learning. It's the reason why some people struggle with new languages while others learn with ease. Those who struggle are playing back slow memorization patterns in their minds, and those who succeed are actually thinking in another language!