Your forgetful zone

The ideal, when you are doing something in another language, is to get so absorbed that you forget you are doing it in that language. That's the zone to aim for. That's the perfect level and form of exposure to encourage.

It's like doing your work as a hobby; you no longer think of it as work. It's like using your tools and sports equipment as an extension of your body. It's like going to see a movie and forget that you exist as a spectator.

Have passion

There’s a German expression to the effect that interest is stronger than love. 

In learning a language, interest overcomes boredom, your strongest enemy. And so, you need to develop passion around your 2nd language. Unless you’re a linguistic nerd, that won;t be a passion for the language itself, but for something that you use the language FOR.

Such interests don’t usually come ready-made. 

You’ll need to 'get into' some style of music, a hobby, some aspect of your target language country’s history or culture. A sport that is big over there. Someone famous you’re interested in. A likelihood of traveling to that part of the world.

Passion is one of the commonest characteristics of almost every successful polyglot and language learner. It makes all the difference.