Here’s an easy way to improve without needing to add any time to your study schedule — think in the foreign language!
How much you can think in the foreign language you are studying obviously depends on your level — don’t try anything too complicated at the early levels. But even if you are a beginner you can mentally repeat the same dialogues which you studied on your course — simple dialogues like meeting people and saying hello, checking into a hotel etc. Try it when you’re on the bus or having a coffee. Just two minutes twice a day can help fix the language which you are studying in your mind.
Up until intermediate level, continue to base your thinking on the language you are currently studying on your course. for example, if you've just been studying past form spend 2 minutes in the morning (try it while you’re cleaning your teeth!) going through all the things you did the day before.
“Thinking in a foreign language” doesn’t mean thinking directly in French, Spanish or whatever language you are studying—at least not at the early stages. If necessary, decide what you want to say in your own language and then think how to say it in in the foreign language. The more you practise, the easier it becomes to think directly in the language you are studying.
At higher levels, when you know most of the grammar and basic vocabulary of the language, you can think about anything you want to! Be careful though. Avoid complex expressions which you haven’t yet studied. For example, if you're at a low intermediate level and want to say If I'd known I wouldn't have gone - you can’t! The verb forms involved are too complex, and you've not yet studied them. So change it to something simpler with a similar meaning: Unfortunately, I didn’t know before, so I didn't go. Now all you need to use is the past form, which by that time you will have studied.
The ability to express complex meaning simply is one of the most important skills you can learn when you're studying a foreign language. To learn more about it see the article Simplify your language!