When I worked for an interior design firm one of my favorite things to do was accessorize bookshelves during installations. When we first moved in to our house, I went to thrift stores and picked up tons of books to fill up my shelves. Awhile back I got sick of the jumbled up messiness that looked more like this (not my actual bookshelves) –
So I decided to clean things up and make the shelves a little more decorative. Without spending a ton of money I was able to use mostly everything I already owned. The key to keeping a cohesive look is decide on almost a “scheme.” Pick 3 or so types of items, textures, etc. and stick with those. For example I used the texture from the baskets, creamy white pottery pieces (the ones I don’t use frequently), some clear class pieces, white photo frames and just a few books to create height. It actually worked out well to use functional pieces as decoration since I don’t have a ton of extra closet or cabinet space in my kitchen.
Accessorizing is all trial and error, try different things, take a step back and see how it looks. As long as lots of your pieces coordinate, either by color or theme it’s easy to mix and match on bookshelves. : )