1. The simplest -Clean your window panes.
2. Install sheer curtains. Remove the heavy solid curtains where possible. Sometimes we have to cut the glare and heat streaming through the openings. In such cases – (this is a professional secret), install Clear glass films from brands like LG, Garware etc. These will cut the heat by 35-65%and maintain the clear vision of glass. These are like the films in the car windows.
3. If possible, place a mirror opposite the window. This will reflect the light and add brightness. You can have wall mounted mirrors starting at Ikea level or have customised framed mirrors hung. Even floor mounted mirror options abound online.
4. Use reflective, transluscent or metallic surfaces for art, accessories like frames, vase, showpiece, cushions etc.
5. Use bright, white shades and colours for ceiling, walls, wallpaper, paint.
6. Don’t bunch too many colours, patterns, textures. Maintain a cleaner, minimalist palette. Highlight using single element to create clear vision.
7. Remove all clutter. Use low heighted furniture.
8. Use floor mounted lampshades to add more brightness.
9. Add plants to bring nature inside the premises. Use minimally designed pots.
10. Add a bright carpet or rug to instantly elevate the brightness metre of the room.

These are some simple, quick and easy to do tricks to bring natural light to any area. Just employing 2-3 of these will elevate you brightness.