Break sectional sofas into smaller groupings to create multiple seating areas, and make the large pieces look smaller.
Paint your walls the same color as your large pieces of furniture. This will allow the furniture to blend in with the walls. Alternatively, use slipcovers on furniture to match your current wall color.
Accessorize the furniture with pillow and throw accents to downplay its size. Allow eye-catching accessories, such as a sparkling lamp or unique wall accents, to become the centerpiece of the room, and take attention away from the large furniture.
Use glass-top coffee tables, end tables, or bedside tables to make the room feel larger, and make the furniture appear less crowded.