Removing the first flower bud before the plant blooms will encourage side branches to develop at the leaf intersections; therefore, increasing the bushiness of the plant. In addition, each new side branch will produce more flowers.
Also deadhead or remove spent flowers to encourage more flowers and a bushier plant. Deadheading will prolong the amount of time that your flower plants bloom. Deadheading chrysanthemums will provide you with another round or two of blooms. Deadheading roses will ensure that you have continual rose blossoms from late March to the frost.