Post wiring my place up loop-at-rose style I found myself wishing it had been done at the switch instead, because the dimmer modules (Fibaro) had two switch terminals and there were two lighting circuits per room. I suppose I could also have had a 7 core (or 2x 3C+e)run between rose and switch to solve the problem. Had sufficient cores gone in, I could have made use of some additional functionality of the dimmer switches (e.g. Hold one switch to dim down and another to dim up- as it stands one has to hold the switch, see which way it dims and if it isn't the way desired, release and hold the switch again). Decide which smart product you want and check it out, wire accordingly
Another tip, and something my spark had never been asked to do; I requested a length of 3c+e be run from one side of every door, up and over to the other side of the door and labelled up as spare. A couple of doors we thought should swing one way, we later changed our mind and had them swing the other way. Having a cable already in the wall meant the light switch could be easily swapped to the other side and the spare cable connected up, blanking panel where the switch used to be, for access to the JBs, without smashing the wall to bits or forever more having a light switch stuck behind the door