Some more out of the box ideas.....

stack vintage suitcases on top of each other to form side tables (dont forget they can be used for storage also)
put old game pieces (like scrabble tiles, checkers, jacks,. marbles, monopoly pieces, chess pieces, dominoes) in apothecary jars or even mason jars for decorations.

put sea shells in clear vases.

glue pretty clear vases to glass candlesticks

cover a piece of foam core board with  fabric and place in a cheap book shelf to give it a face lift.

use plates as wall hangings, plates all in a like color can make a great grouping.

so can different size mirrors, can be combined to make a large statement.

you can often find clocks fairly cheap, group them together to make a attractive display.