Change out your plain tiles with more decorative ones, such as replicas of vintage metal tiles. If you have existing acoustical tiles and the new ones aren't, keep the soundproofing intact by slipping in the new decorative tiles underneath the acoustical ones in your grid, so that the decorative tiles are visible but the acoustical ones are still behind them.
Replace any broken or damaged tiles with new ones that are uniform in appearance and size (if not replacing the whole ceiling with different ones). Bring one of your old tiles with you to your local home improvement store to ensure that you get the right product.
Clean any dirty tiles using a chemical sponge if they are older and porous. Use a damp sponge if they are of the newer variety with a washable finish.
Paint the tiles a color that ties into the rest of your decor choices, using a small roller or brush to spread the paint evenly. If the tiles are acoustical, use only one or two layers of thin paint, making sure not to fill in the holes or fissures, which would limit their soundproofing qualities.
Paint the grid to spruce it up for a cohesive-looking suspended ceiling. Paint it the same color as the tiles to blend it all in, or an accent color so that the grid pattern is a focal point in the room.
Paint a pattern on the grid that matches the rest of the decor in your room to make the ceiling stand out even more. For example, use a stencil to create an ivy pattern or scrollwork design.
Replace older light fixtures with newer, more contemporary ones to make your suspended ceiling look good. Newer lighting will showcase all of the hard work you put into transforming the ceiling.