As an example, I have several different styles and sizes of candle holders that used to be scattered here and there throughout the house. When I decided to redo the display on the top of my piano, I was loath to find the right items to display. Then I thought about the candles and decided to make an entire display of them on the piano top. The outcome is pleasing and when they are all lit it doubles the impact of the display. As well, having all of the candles and holders on one surface adds importance to them whereas having them scattered here and there tends to make them disappear visually. Even though they are all different designs, shapes and sizes, displaying them as a grouping makes it OK to mix and match.
A good place to start this grouping practice is with family photos. Framed photos scattered here and there can seem more like clutter. To give them the importance they deserve, display them in a grouping in a place of prominence, whether that be on a table or on the wall. Even if the frames don't match you can still get away with a successful display as long as the frames are in the same visual realm. (For example, metal and wood frames will go together but you might leave the ceramic, baby photo frames with bunnies and kittens on it for another room.)
Hanging several smaller mirrors on a wall rather than one big mirror can be an unusual but effective focal point. Collect smaller, inexpensive or even antique framed mirrors and create a wonderful wall display over a sofa, at the head of the bed or even as the main mirror(s) in a powder room. Play with the layout by mixing square and round frames and by turning some of the square frames to hang in a diamond pattern. Get creative!
Painting, especially original works, can become more dramatic when leaned in a grouping of three or five on a mantel or wall shelf. This prompts people to stop and take stock of the artwork instead of walking past single paintings hung in a hallway or foyer. Mix large and small paintings for added drama and change the display on a rotation basis to keep it fresh and interesting.
Plants can add tons of texture and colour to your space but rather than one single plant in a big pot, try planting two or three compatible plants in a decorative planter. Group small potted plants in threes on a window ledge or table top for added interest.
One or two toss cushions look nice on a sofa but five or more will speak to comfort and abundance. Mix and match colours, shapes and patterns for huge impact on a plain sofa. Group them at each end or all in the middle of the sofa for a more interesting look. The same can be said for accent pillows on the bed. The more, the comfier.
In the bathroom, display those lovely bath towels by rolling them up in a grouping in a decorative basket or on a storage shelf. A basket of soaps is another nice touch.
Inexpensive decorative storage sets for the dresser or vanity are another great way to create visual interest while providing countertop storage for utilitarian items. One storage box is OK but a set of them creates more impact.
To start, gather like things
If you have two or more of anything, you might be able to make a nice grouping out of them. For example, you may have wicker baskets or containers here and there throughout the house. If you put them together on a shelf or an open cupboard you suddenly have decorative display that can be used in the bathroom, kitchen, home office or even the bedroom. Perhaps you have a few vintage Campbell's Soup mugs in the cupboard. Put them on display on a shelf in the pantry along with your soup cans and suddenly you have a collection rather than old, loose mugs kicking around. Maybe you're a crafter like me and have handfuls of beads, river rocks and coloured sand in your tickle trunk. Place them in clear, decorative containers and group them on a ledge for an instant mini-focal point or use them as a centrepiece on a dining table.
Food as art
Dried, coloured beans and peas can be placed in decorative, clear containers and grouped as a display in the kitchen. Even coloured pasta works for this easy project. A handful of lemons or limes, displayed in a tall, clear vase, will make a great centrepiece as well. Pull out all of those fancy vinegars and oils from your coffers and make a decorative grouping of them in the kitchen to show off your gourmet skills.
Look around your space and see what your creative mind comes up with. Keep me posted!