okie dokie no jokie,
Izotope has given us the low-fi simulator plug-in Vinyl for free, as a 15th anniversary present.
It has settings to emulate the sound of a scratchy record, with parameters for the surface noise of the vinyl and also the warbly sound of a motor which does not play at constant speed.
Vinyl is handy for adding some texture to those digital sounds which are just way too crisp and clean. You can exxagerate it for a vocal sample, or run your sweeps and risers through it to use during a breakdown where it will be more obvious. I haven't tried it on a whole mix yet but that could be cool too, especially for something like an acoustic band that needs some woolieburger on it.
How To Use
I put Vinyl in the same category as my saturators -- they're things to add early in the FX chain.
Somehow I get better results when I use them as part of the sound-shaping, instead of strapping them on at the end and wishing for some big magical change.
Another way to say that is you might want to use a high-pass filter after Vinyl, to avoid low frequencies which do nothing for your sound.
Subtlety is the name of the game.