Quoted from zaki:get cleaning supplies. novus 1 for plastics, millswax for playfield. i forgot the name, but the cleaner for rubber stuff on the slings and flippers, posts. you'd be surprised how much dirt it takes off.
avoid mods. been there done that, doesn't add much.
Millswax contain silicone so I would not recommend that product for playfields. Use carnuaba wax products instead, like Blitz Grand One or similar and a sponge applicator.
Novus 1 and 2 are great to have too. Just don't use nr 2 too often (it's abrasive).