It comes together with practise. You will find that larger control inputs are required at lower speeds.
Aim for the first 100 yards of runway. Point the aeroplane at it. If you aiming point rises in your field of vision, you are sinking relative to it, so you apply a little more power to arrest your descent. If its starting to creep towards the bottom of the windscreen then you need to take some power out.
Once you know what the picture is supposed to look like and you can fly reasonably close to your desired approach speed, you'll have it cracked.
When flaring, look out at 45 degrees to get a good picture of what attitude the aeroplane is at and how high off the ground you are.
You may find that a simulator helps with the speed control during the approach. Unfortunately you need to flare for real to get that skill.
When it comes together you'll be very happy. Its a good feeling indeed.