Could you be a little more specific or describe your theme?
Things like repainting, potted plants, candles...
Here's what Pinterest can offer you:
Have pictures ?
I would determine a color scheme, what sort of decor theme you want (farmhouse, beachy, etc.) and then look on Pinterest for ideas.
I watch a lot of Home and Garden TV. Their designers always say to use space in thirds. One-third books, one-third chachkeys, and one-third open space.
Here is a post about decorating shelves that are wrapped. I think this will give you what you need on decorating your entertainment center https://lifeonsummerhill.com/how-to-decorate-a-bookcase/