Is there a tool in ArcGIS that will make the output raster completely encompass the vector boundary? Somewhat similar to select by attributes where all overlapping features however minuscule is added in the selection. What I do now is create a buffer around the polygon with the distance same as the cell size of the output raster I want, but this is an extra step which if has a proper tool (or setting) counterpart will greatly streamline my workflow.
There are a couple of approaches. The first is to use GDAL for the conversion (it is free and available with a UI through QGIS or you could use its Python bindings as part of a ArcPy script). GDAL has an option for "All Touched" which does exactly what you want.
Sadly ArcGIS does not offer an 'all touched' option for polygon to raster conversions. However, there is a work around in Arc which is successful in some situations. Set the priority_field to the field you are using for converting the polygon. You may also have to set cell_alignment to MAXIMUM_AREA. This way, null values get overridden due to the priority field.
The first method is a sure-fire solution which you can use either inside Arc if you have some basic scripting abilities, or in QGIS. The second method exploits a quirk of ArcGIS and may be less predictable.