Simply use a classes .btn
.btn-default
and quickly create a general button.
Simply use a class .btn-rounded
and quickly create a rounded button.
Simply use a classes .btn-lg
.btn-sm
.btn-xs
and quickly create a different size buttons.
Simply use a class .btn-block
and quickly create a full size button.
Use a class .btn-group-vertical
Use a class .dropdown-toggle
and also add data-toggle="dropdown"