This is a great topic!
Here is my formula for making games more difficult:
- Set game specific rules to hard (or in some cases easy - I set Last Crusade on IJ08 to easy, as you get locked into that mode).
- Reduce time to complete modes, re-light MB, etc.
- Turn off Ball Save.
- Turn off Exta Ball.
- Turn off additional ball save features, like the pop up post on Harley Davidson or Family Guy.
- Widen outlanes.
- Align flips slightly lower. I may investigate different coil stops to allow for proper resting-flip alignment, but less travel, and therefore less ability to trap, if possible.
- Tighten tilt.
- Adjust Kicks and Pops to be more sensitive.
- Install 23/64" black rubbers on inlane posts - less up bounce at outlanes.
- Remove inlane post rubbers on some games. I have Sopranos and Dirty Harry this way.
- On center posts I either remove the rubber, or install a black 23/64". I don't remove the post, though.
- I've put lightning flippers on games that shouldn't have them. I did this on Batman Dark Knight.
- Install regular white rubber on kickers.
- Install Titan rings on all single post applications. If above outlanes then more down bounce.
- Install SuperBand rings in multi-post ring applications. If above outlanes more down bounce.
- Install SuperBand post sleeves where applicable - huge rebound in my experience, very punishing for missed shots.
- Use regular flipper rubber. Red and yellow are my most used. I think these make trapping harder, but that may also be an incorrect opinion on my part - I was told that black rubbers may be more difficult, but I ain't cleaning up after that crap.
- I haven't tried this on my EMs, but I heard folks use to replace stock pop bumpers with the next-following generation pops, so that they are more powerful. I'm not sure if this is actually doable, or smart, but it sounds interesting.
- Clean and Wax.
My decision for Titan or SuperBand rings is also to limit maintenance, as they should last longer than regular rubber. I don't mind rotating and changing Flipper or Kicker rubbers more frequently, and I prefer the feeling of these over Titans or SuperBands in these applications.