The practise advice is the best advice out there. As for technique to use, you may wish to consider the following alternative.
Firstly, when on finals, select an aim point which is short of the touchdown line. By doing this you will take into account the additional distance beyond your finals aim point that you will use up during the flare. In your practise sessions, while on finals, aim for a specific point on fthe runway and see where you generally touchdown in relation to that aim point. This will indicate to you how far before the touchdown line in the spot landing competition you will have to aim for while on finals.
Next, when it comes to your aim point, when you roll out on finals on what appears to be the correct glidepath angle, actually point the aircraft at the aim point, i.e. use pitch to control your aim point. Consequently, you will use power to control your airspeed.
We use the 3 x A phrase "Aim point, Aspect, Airspeed" as the scan down finals. That is, when you look out the front, you assess whether you are actually aiming (pointing) at your selected aim point, at the same time, you assess whether your aspect is correct, i.e. whether you are high or low on your intended glidepath angle.
E.g. if you assess that your aim point is correct (correct pitch attitude selected) but you are high on your intended glidepath, then you aim the aircraft (lower your attitude) to select a new aim point short of your intended aim point. This will bring you down on to your intended glidepath. Of course, as you correct down on to your intended glidepath, your speed will want to increase, so you reduce power to maintain your airspeed at the correct approach speed. Anticipating the correct glidepath, simultaneaously raise your attitude to reselect your intended aim point and increase power to maintain your approach speed.
The reverse applies when you are low on glidepath.
See how mormally that your pitch changes and power changes will tend to work together to maintain the correct flight path vector and airpeed.
How do you know what your aim point is? Answer - If you fly a constant speed approach, that point in your windscreen that does not move is your aim point. So if your selected aim point slowly moves up your windscreen as you progress down finals, you are actually aiming short of your intended aim point and consequently, you will end up on a lower glidepath than you want. In this case, raise your attitude so your aim point does not move in your windscreen (and add a little power to prevent the speed reducing with your higher pitch attitude).
If you can peg your aim point, glidepath (aspect) and airspeed, just flare normally and your wheels will squeak on, right on the line. (Wishful thinking!!)
Anyway, it's food for thought.