When you create most of the solid 3D modeling operations, there are following checkboxes available in the Options tab of the Parameters window (availability of certain checkboxes depends on a particular operation):

Blue and red arrows |
Manipulators |

Blue edges |
Wire-frame preview |

69 and 85 |
Labels of key dimensions |

Yellow surfaces |
Dynamic preview |

Use Manipulators

Enables manipulators in 3D scene. Also enables wire-frame operation results preview, which automatically updates upon changing parameters of operation. Set of available manipulators as well as availability of wire-frame preview depends on a particular operation.

Show Labels

Enables labels of key dimensions in 3D scene. An icon depicting a dimension type is shown on left side of a dimension value. Set of dimensions available for using as labels depends on a particular operation.

Dynamic preview

Enables operation results preview in form of yellow surfaces which automatically update upon changing parameters of operation.

Create Driving Dimensions

Allows to create Driving Dimensions in 3D scene along with the current operation creation. Not all dimensions defined in operation Parameters may be used as driving dimensions. Set of dimensions available for using as driving depends on a particular operation.

Simplify Geometry

For some operations General Parameters or Additional Parameters tabs of the Parameters window have the Simplify Geometry checkbox. Enabling this checkbox will allow the automatic simplification of the resulting geometry. Spline-based surfaces will be replaced by analytic surfaces (segments of cylinder, sphere or torus) where possible.