It will likely take a few episodes, several hair-pulling late nights, and a lot of tears before you get a winning structure down so my advice is to plan as much as you can before hitting record. Which brings us into the next section. Improvising on an instrument isn’t hard once you have a level of technical fluency. You can play whatever notes you want in whatever order you want to play them, with whatever tone and attack. Scratching is more limited. The music in the recording is set already, it’s in the order that it’s in, and it sounds how it sounds. Any expressive moves you make have to make sense in relation to what’s happening in the recording.