Read this thread also
https://forums.frontier.co.uk/showthread.php?t=109990
I'm currently using a Kitted out Python and making about 3M Cr/Hr mining a Pristine metallic ring. As Gorrister says, forget the Asteroid Belts and RES's and just fly into a ring (normally the inner ring) at slow speed, you will drop out of SC and then mine away.
Check out this site for Pristine sites near your location
http://www.hozbase.co.uk/EliteDangerous/, then dbl check on the Galaxy map, in case their status has changed, also pick a system where a port is close to the ring.
Try and use a 4A refinery, that has 10 bins and I use 2 x collector limpet controllers bound to the same firegroup which gives me 5 collector limpets at any one time to collect rock fragments.
I find mining curiously calming, almost zen like.
One other tip, when you get back to the station before selling your metals/minerals, check the bulletin boards for any missions requiring metals, I made 250,000Cr yesterday for giving them 3 Platinum where I would only have made about 60,000cr if I had sold them in the market
