Marie Kondo, the queen of decluttering, advises you work by category, rather than room. To make the task of decluttering easier, she suggests you tackle them in the following order: clothes, books, papers, miscellaneous and sentimental.
The KonMari Method™ involves picking up each item and thinking about whether it sparks joy. Keep only those things that speak to the heart and discard items that no longer serve you. Thank them for their service – then let them go. Don’t be too harsh and start getting rid of everything, as being too extreme might cause you to panic and rush out to the shops to fill the gaps.