Output practice methods?

I’ve been focusing on reading, listening, and learning vocab/WaniKani drills. Now that I have a good base in input, I want to start improving my sentence production. Both speaking and writing.

N4 might be a bit low, but I figured it’s a good starting point while I figure out my next steps. What methods did you all use to practice active production? Right now, my biggest bottleneck is that I lack enough active vocabulary. Any advice would be greatly appreciated!