Generally altitude x 3 times with 1 nm per 10 kt reduce in the speed works well in my experience but what I did (and actually still do is); I enter the runway or the faf to the PROG page and make all the calculations and planning aloud, like "ok we have xx nm to faf, we are at xx feet, we are high/low, I will do this/that", then as written above everyone in the cockpit knows you are aware of the situation and have a plan, and secondly everyone will share their experiences based on the situation.