Congratulations
@sone , great strategy!
I personally focused on gaining as many level 1 skills as possible with my sims, mostly by reading skill books when it was possible. I also added skilling objects to the houses for skills that cannot be learned by reading books (veterinarian, cross-stitching, pipe organ, media production...).
Except for my last household, I only played with households that already had a sim with a max level skill and, as
@sone did, adopted toddlers to have more sims in the household (and make them gain level 1 to all the toddlers an children skills before aging them).
As soon as most of the household members had level 1 in all possible skills (except selvadoradian culture that I didn't know how to gain without travelling to Selvadorada and pet training because I did'nt want to keep a slot in the household for a dog) I went playing another household.
That was my strategy for the 5 first households I played: Bjergsen, Moody & MacMillan,Laurent, Ito and Scott and each household got 400 to 500+ points. I chose them because one of their members had already max a skill and also because of the total amount of points the household already had.
On the last day I went playing with all the households with a maxed skill I didn't already play: Vladislaus Straud, Rasoya, Behr, Romeo and LeChien and Delgato.
I did not try to increase their skills, only noted the points they already had.
Then I played a few hours with Watson family : they already had many points, and one of the children has level 7 in Motor skill so it was quite quick to get to level 10 while the other members gained as many level 1 skills as possible. The Watson household finally gave me approximately 200 points.
I ended the challenge with the 5 members of the Robles household (some of them had already many points), who gave approximately 200 points too.
I took much time planning which households to play, regarding to the skills their members already had, and learned many things about our premade households!