When my Sims start out they're usually in a cube with plain walls, one bed, a shower, and a fridge (or the cooler). I don't normally decorate with clutter items until I have enough money to build a proper bedroom/kitchen/bathroom. Then I add some basic clutter, the roll of TP, an (unused) laundry basket in the bathroom, the decorative lemons in the kitchen, 1 wall decoration in each room. Not a lot. Eventually I build up to having 1-2 super expensive items/clutter objects in each room to give the Sim a "well decorated" moodlet. Usually when I consider their dream house to be 'done'.
Though I just got Parenthood so their home is VERY cluttered with toys and projects and items for that. It does make a change for me and I don't mind that playstyle either!
If I download a finished house from the gallery (some houses I can desig myselfn, some I can't do well, like Art Deco or Modern), I don't prefer an item on every single available slot/surface of the house. When every console table has 3 or more items on it, and every side table has an item, and every shelf has multiple items... Then my sim gets something from their career/brings a project home and I can't place it anywhere... I can't cope lol.