Reusing sketch geometry can save you quite a bit of time in SolidWorks. Rather than creating multiple parallel sketches to produce different features, you can create a single sketch which can then be used for multiple features. This can be achieved using the contour select tool or the select contour box, in the property manager, for several features. The contour select tool can be accessed by right clicking in the workspace, as shown below.
The tool then allows you to select out specific areas of a sketch, which automatically populate into the select contour box when you choose certain features, for example the extrude boss/base. To reuse a sketch for subsequent features, simply show the sketch and repeat the process.
If you plan on taking the CSWP exam at any point, the first section of the test is considerably smoother if you use as few sketches as possible, and employ the use of the contour select tool. See the full tutorial below: