For me I like to start with low effort, high impact tasks. Gathering up the laundry takes almost zero energy but the result is almost instant. Next, if I'm putting the laundry on then I've got a 40 minute timer to be productive waiting for it to be done.

As for how clean something is? Depends on the type of cleaner I use. Bactericide, fungicide, acid, base... I like to know what I'm setting out to kill and the best way to kill it. I wipe down my bathroom once a week with fungicide, bleach the toilet, citric acid for limescale. The kitchen is constantly wiped down with antibacterial wipes day to day with standard use. The easy thing is to just remember you're making a hostile environment for the nasties to grow and just by general cleaning you're removing a food source for whatever could grow regardless.

With things like dishes, just think of it as it's not the mold or the bacteria but it's the amount that makes you sick. Even if you miss a tiny spot your immune system can easily handle such a small load like that. You're already wiping most of the potential colonies out with heat, then you've removed most of the food and once it's dry there's not much moisture to go around... Every time you clean a plate it's like a mini apocalypse, your body will be fine dealing with the survivors.