the rules of thumb mentioned so far are all fine and good but it can be a bit cumbersome to always have to fight your way to some fixed alt/distance point.
i found these figures quite helpful when i flew the brazil nut:
(these are for clean config, no speedbrake, idle thrust)
- in level flight the embraer slows 10kts every 1nm
- in a 1000fpm descent it slows 10 kts every 2nm (or 10kts/3nm if you're heavy; +1nm for every 10kt component of tailwind)
you can use this to work your way back from whatever restriction you need to make on arrivals (or at least know if you have a chance of making them or not). you can also use this to ensure that you make 200kts and 3000'agl by the time you get to the IF.
either do the mental math or just use the fms to give yourself 1000'fpm descent segments by hardening altitudes at appropriate waypoints or building a P/B/D with alt restriction to make it happen.