You could try Instantaneous Composition Method, which is a method of hearing a simple sentence in English, thinking what the equivalent would be in Japanese, saying it out loud, then repeating back the Japanese used in the lesson’s audio file. The idea is that through repetition, the time it takes for you to think of the Japanese and say it out loud becomes instantaneous.
There’s an article with a more detailed write-up as well as links to audio files used to practice.
here’s also a YouTube video with another chance to practice
Another approach would be to start narrating your day in Japanese. Think and/or say quietly to yourself what you’re doing at the moment you’re doing it as you go about your day. This gives you a chance to practice speaking Japanese as well as recall words you know.