This could spark quite a discussion about timing of steps, but I would say that in general you want your "center" to be over the 'placed on the floor' stepping foot "on the beat," rather than beginning a step "to the beat."
Maybe that's what you meant?
And, yes, it takes lots of practice. Otherwise we would see more people actually dancing in time to the music.
For once, a post with which I can entirely agree!
But have you ever seen it taught, and in a way
that people can comprehend and execute?
I heard it once briefly mentioned that the stepping foot
should be weighted but without any explanation of how
it should be done.
Don't look to tangoandchaos.org for much help either
because Rick McGarrey was very inconsistent.
In my experience you have to change your posture
in your embrace, the way your foot strikes and
your perceived timing of landing the foot relative
to the position of your body. The foot lands positively
on the beat giving you an immediate stability to
release the previously weighted foot and increasing
the time between the steps.
The travelling foot is actually delayed at the centre so that
the front of the foot can land on the floor to meet the body
weight as it arrives and thus the foot is immediately weighted.
The weight transfer is much faster and changes the emphasis
from one of slow and continuous weight transfers towards
a dance emphasising a connection with the beat yet with
repeated and extended centered axes.
It's that time "in the middle" which allows you to reflect
the music, to change how you move to the music, or by
omitting beats to not even move at all or very slowly.
Much more becomes possible in the moment.
A two footed dance (see tangoprinciples.org) becomes one
of repeated single footed axes. Getting this right for me
took much longer than I expected but it changed my
perception of the dance and how it was actually possible
to feel as if you were dancing the music.