I mean, I always have something in mind whenever i try to start a new settlement (via re-embarkment, of course) like specializing in a certain aspect such as mining, farming, trading. However, every time I work towards that particular goal, all of a sudden I end up with a lot of clutter like ores and other excess materials in each and every of my playthroughs. I do also try to improve on my building designs so that my town would feel more alive and bustling, but it ends up with the the hearthling-to-building ratio being kind of unbalanced; like a big looking town populated only by a handful of hearthlings.
So I wonder, how do you guys make each of your playthroughs fun and consistent?
well in my case because im still adding to my hearthlings i always have new toys to paly with XD
but beyond that, desinging new buildings, refining old ones, and multiplayer helps, learning from other peoples designs etc 
I generally play this game whilst recording, so I have an idea of a town that I want and over the Let’s Play, I tend to build that. Next to that mods will help (Going to use those in my next playthrough), and sometimes I just play to build over the top things… yay