Doesn't happen all the time obviously because of ATC vectors away from the mental path you may have. The 300ft/mile is a good basic rule but for most aircraft I find this requires a "power on" descent given the majority of jet aircraft can descend around 1000ft every 3 miles on idle power.
I swear by gates. 8000ft/250kts downwind, 1200ft/min gets it slowing down and going down gently without having to use power to arrest descent. Gets a bit twitchy at times (especially in the bus with the well known balloon when selecting flap 2!) But like with majority of companies, ours doesn't offer any advice/practice on CDAs and therefore those gates mentioned above often scare the guy in the left seat. Not sure if this is because they don't have faith in me or prefer to keep it straight forward.