As far as good speeds to downshift at in a freightliner 10 SPD I do 9th at 45 mph, 8th at 35 mph, 7th at 25 mph, 6th at 15 mph, 5th under 10 mph but coming to a stop you can stop in 6th or so as said prior get it stopped instead of focusing on downshifting. I found what works good is clutch in, neutral, quickly push gas pedal to floor, then quickly clutch and grab gear. Also when I first started the 9 to 8 downshift was beating me up. On that just gently push the shifter toward left and it will want to sit right in front of 8.
As far as good speeds to downshift at in a freightliner 10 SPD I do 9th at 45 mph, 8th at 35 mph, 7th at 25 mph, 6th at 15 mph, 5th under 10 mph but coming to a stop you can stop in 6th or so as said prior get it stopped instead of focusing on downshifting. I found what works good is clutch in, neutral, quickly push gas pedal to floor, then quickly clutch and grab gear. Also when I first started the 9 to 8 downshift was beating me up. On that just gently push the shifter toward left and it will want to sit right in front of 8.