You should keep in mind all possible traces: the file itself, its shadow copies, old data stored in file slack space, parts existing in the swap file, the file name stored in MFT, directory slack space.

BCWipe takes responsibility for properly wiping all of these places. It is typically best to follow all BCWipe recommendations and click 'Yes' to any cautions. On the ‘Wiping option’ tab, it is highly recommended to enable all options.