Hi WST
First, you have to be aware that it is your altitude what determines how many track miles you need. If you have more miles, you are low. If you have less, you are high.
Then, you can only know if you are high or low if you know your distance to go, which not always happens.
In the 320, this rule of thumb works very nicely: FLx3 plus 10 (when you are above 10,000 ft at ECON speed, typically about 290 kt) and only plus 6 when below 10,000 ft at 250 kt. If at green dot when being vectored in approach, FLx3 plus 3 miles. After S speed, FLx3 plus zero.
In your next descents, when using DES and on profile, check if I am right or not (note: if you activate approach before the Decel point, the VDEV is no longer valid because it "thinks" you still have 250 kt. I can tell you are high when you are not. A few miles after the Decel point it will become valid again)
Wind effect is about a 5% of the distance per each 20 kt of wind component.
In descents I regularly check my gradient, both in the air and relative to the ground, with V/S and TAS or GS. Sometimes air gradient on which I base the rule of thumb is steeper or shallower, then I know that I will have to correct.
In latest models THR IDLE is not a real idle, it is increased, so in DES the path is shallower than in OP DES.
During descent you can calculate if you are high or low relative to the FPLN miles and also direct distance to the runway. If the difference is significant and you don't know if you will be given a short cut, you have to bet for one option but be prepared for the other.
Far from the runway, use speed increase to correct a high on profile situation. Closer to the runway use speedbrakes and when close to the approach, reduce speed, maybe using speedbrakes, and get some flaps.