The effectiveness of soundproofing methods depends on various factors, such as the level of noise, the construction of the room, and personal preferences. However, some commonly used methods for soundproofing a room include adding insulation materials, sealing air gaps, using double-glazed windows, and installing acoustic panels or soundproof curtains.  The best method for soundproofing a room depends on the specific needs and circumstances of the space. Therefore, combining multiple techniques to achieve the desired level of sound insulation is often recommended. Consulting with a professional or conducting research specific to your situation can help determine the most suitable method for your needs.