Be realistic.
While decluttering what's redundant/ not needed is important to free up space for what you need, love and to live, different people have different levels of stuff they need, different spaces, ways of functioning and different comfort levels.
There is no point in me aspiring to live in a minimalist gallery home because, out of sight is out of mind- I need visual prompts to function. I don't cope with tidying as I go because it distracts from my primary purpose and I end up drifting off from it on various tangents. I am naturally stuff-y; I need the physical books, CDs, DVDs, the different types of running shoe, the two types of wetsuit, the three types of swimming goggles...
There's no point in me aspiring for perfection because it turns into a frustrating, unattainable battle against myself.
But what I can do is:
*Allocate spaces for what I have, and not exceed them.
*Arrange transient items better e.g. in baskets so they are contained and review when full
*Be efficient with storage to maximise what I can do with the limits of my home.
*Keep spaces clear. Most of a floor should be free- there might be frequently used shoes lined up at the edge of the hall because it's not worth traipsing them round to the shoe cupboard when they'll be worn within 24 hours.
*Zone- Some surfaces at high traffic points are natural clutter points so work with it, and contain with baskets. Keep other surfaces free for ornamental use only. In the kitchen, the first 18" of workspace by the door is permitted for general items. There's then utensils as a small buffer, then there's the food preparation zone. When the kitchen was redesigned, we got rid of the breakfast bar because it was going to inevitably be a clutter battle zone and took up floor space for little practical storage gain by creating an awkward corner unit.
Looking at my lounge around me, it's currently a mild mess, but in 5 mins I can put the discarded socks/ layers of clothing into the downstairs laundry basket, pick up a couple of wrappers for the kitchen bin and take a couple of cups out, put the fitness equipment back in its cupboard. The clutter basket is OK. Fold the blanket and whizz around the middle with the vacuum. It won't be an in-laws visit grade clean, but it will be tidy and functional.
There isn't a single correct method and there isn't a single correct standard. However if the state of stuff is blocking your ability to do things, then it's too messy.