Rebuild the flippers = new plungers and coil stop. That makes the flipper travel a shorter distance which makes it harder to trap the ball. That along fresh soft rubber rings on slings and flippers. And you'll find everything that area chaotic.

Second a fast playfield. Which may only be possible to a certain extend relative to playfield wear. I hear wax recommended. But I havn't any experience with that myself.

One thing people perhaps tend to forget is the standup targets. Replacing the pads behind the actual targets with a hard bouncy material, make them more unforgiven. Random rebounds to them may not be hard enough to register. And direct hits become more dangerous.