Do a 3 second scan. Walk into the room you want to decorate with your eyes closed, open them, then scan the room for 3 seconds. Write down the things that bother you the most from that 3 seconds. That way you aren’t getting overwhelmed by all the things that you want different and changed. Use that as a starting point for redecorating.
Convert a bookshelf into a storage-friendly bench. Turn the bookshelf on its side and add panels to each end. Add wooden furniture feet. Paint the piece to complement the colors in your space. Throw a cushion on top and it's complete.