Maybe everyone already does this, but - in TS2, when you place a new lot, the direction the sun shines is set in stone depending on what direction it was placed in the neighbourhood, regardless of how you move/rotate the lot in the future. Ideally, you want the sun to be shining on the front of your house, but I'd always forget what direction that would be, and have to check manually.
Then I came up with this - I created a small empty lot, put a couple of walls up to see which way the sun came, then drew a diagram on the ground using floor tiles. Now I can see from neighbourhood view what direction the sun will shine on newly-placed lots, and place them accordingly :)
I'm in the process of creating Appaloosa plains in The Sims 2 💖 I will be recreating every single build and creating every single Sim in The Sims 3 pets..