Do you customise worlds before playing?

When it comes to EA worlds, I basically redesign and rebuild the entire town to fit my vision of how I think the world should look, feel and work. I leave the original map layout as it is changing only the locations of the businesses and housing. Because I prefer to play in mostly rabbithole-less worlds, I custom build all of the homes and business in the towns to suit my population.

I only do this once and make a Master File of the world to use as back-up should things go wrong. I start with a new game, immediately go into edit town and begin making the changes I want such as demolishing house, removing Sims adding homes or community lots. This is done over time and not as an all-in-one go.

In the meantime, while I am working on my Master File, I play my game in what I call temporary saves. In these saves I work with each household who is to become a permanent resident in the new town when it is finished. This is where I help my Sims skill up and develop. Once they are ready, they are saved to the library where they await their turn to be added to the finalized town.