Don't fight against your own brain
Simple fact: it's your brain that does your learning for you. It knows more than you'll ever know about how to learn. So when you're trying to learn something and it just isn't sticking, don't fight against your brain -- you're brain's telling you you're doing it wrong.
So how do you get your brain to accept new information? The new information has to be meaningful, first of all. If it doesn't mean anything to your brain, your brain doesn't want to know.
Unless you need to learn certain specific words, the best thing to do is to start anticipating what you're going to want to say. Lots of courses try to do that for us, but they can only anticipate what we're going to want to say at some point. Only you can determine what you're going to want to say now.
To use a fairly obvious example: holidays.
If you're going on holiday, you're going to tell people about it. It's not a matter of showing off, either: you have to explain to people that you're not going to be around for a week or two. Once you say that you're going on holiday, people are naturally going to ask you about it. So before you tell anyone you're going on holiday, you can have a good guess as to what you're going to need to know to answer their questions: the name of the place, the type of accommodation, words such as "beach" or "mountain", "package tour", "ferry", "aeroplane" and so on. This is stuff you know you're going to be asked about, and it's stuff that you're probably thinking about lots already anyway. This is the sort of stuff your brain wants to know.
But even if you don't think you're going to get enough practice, remember that most people aren't personally invested in other people's holidays, so they don't tend to remember the details. This means that when you're back and they ask about your holidays, you get to repeat a lot of what you said before, as well as going into further detail.
I go to weekly conversation groups for several languages where I speak to different people each week, so I find that my holidays are a topic of conversation for two or three weeks before going and two or three weeks after coming back. Talk about the same topic for over a month and a lot of it sticks
Even better is when your holiday destination is where the language you're learning is spoken, not only because the vocabulary will be relevant to you when you're out there, but also because every time you meet someone from that country they'll ask you if you've been, and your answer will revolve around this same holiday. My last holiday was in November, and part of it was spent in Barcelona. It's nearly March, but I've spoken about that holiday at least once every two weeks since, because every time I speak to a new person in Catalan, they ask me if I've ever been there.
Does the topic of holidays seem limiting? At first glance, yes. You look at language books and holidays are all about flights and passports and beaches. But when you're on holiday, you've not stopped living. Life carries on. You still eat and sleep. Sometimes you're woken by people coming back to the hotel drunk in the middle of the night. Or maybe you have a noisy couple just down the corridor. All these little slices of everyday life become stories when you come back from holiday.
Stories from my last holiday include talking about trying to find an internet café through the medium of Catalan; turning up at my hostel only to find it's in the middle of the red-light district; a sleazy Italian trying to pick me up on a secluded beach; a flight cancelled for snow; overnight trains and speed restrictions.
I come back wanting to talk about these things. But in talking about these exceptional events, I don't just need words specific to the individual context, but I often find I need more mundane, everyday language that I just didn't know before.
Listening to your brain
Most of us, as language learners, develop an ability to avoid holes in our knowledge. You don't know how to say you're going to do something? You just say that you will do it instead. We become adept at spotting these potholes and swerving to another way of saying it. The better we get at this, the less we notice it, and this becomes a problem, because at that moment, the brain is telling us exactly what it wants to learn. If you want to say it, it's because the brain wants to know it. So when your brain says it wants something, take note of it, whether on paper or mentally.
Learn to listen when your brain asks for language, and you'll find that it's always asking for new words, and it will keep you busy for a long, long time.