Also try using some interesting weeds from the countryside. Plants are always attractive and nice for filling empty spaces. Use decorative pillows. They can be inexpensive, functional and attractive. Use books to add color, texture and design to an area.
Candles can be simple but decorative.
Frame a fabric. Frames can be purchased or made. Stretch the fabric over the frame and staple. Baskets can be decorative in every room of the home. Use them on the wall, under a plant, on a shelf, to store clothes or linens, etc.