On long coasts i turn the engine off, most of the time i leave the engine on. A long coast for me starts at 1/3 to 1/2 mile or i find it to bothersome to do.
I drive a mountain pass that allows coasts of 10 km's but you need brakes so the engine stays on, on the long steep hills. My cars brake booster goes flat after 3-4 applications of the brake, or one solid stop if not going too fast,with the engine off.
Test your cars braking with the engine off so you know its limits.
Pump your tires up, my tires are at 50 psi, it dramatically reduces the rolling resistance, allowing extended coasts.
When driving a manual,shift as early as possible without lugging the engine. A increase in RPM's equal a increase in fuel consumption so try not to race the engine.
It will become second nature in 2 weeks or a month of practice, then you will be doing it automatically, or so i have found.
And remember enjoy your driving !
& the new challenges that will take the boredom out of the drive.