I like this piece: Why We Clutter, and What to Do About It – The New York Times. If you never decluttered your place before, it’s a good place to start.
Decluttering is like dieting though: you can make an effort to cut back, but unless you address the thoughts and behaviors that lead to clutter/overeating, you may end up back where you started.
I recommend while you are decluttering to take note of what you have excess of. Is it too much paper, clothing, books, utensils, tech stuff, or something else altogether? Those are the areas you need to focus your analysis of if you want to have any hope of living with less clutter. In the end you may be fine with periodically paring down the amount of clothes or books or stationery you have from time to time.