  The use of high resolution, high signal-to-noise stellar spectra is essential
in order to determine the most accurate and precise stellar atmospheric
parameters via spectroscopy. This is particularly important for determining the
fundamental parameters of exoplanets, which directly depend on the stellar
properties. However, different techniques can be implemented when analysing
these spectra which will influence the results. These include performing an
abundance analysis relative to the solar values in order to negate
uncertainties in atomic data, and fixing the surface gravity (log g) to an
external value such as those from asteroseismology. The choice of lines used
will also influence the results. In this paper, we investigate differential
analysis and fixing log g for a set of FGK stars that already have accurate
fundamental parameters known from external methods. We find that a differential
line list gives slightly more accurate parameters compared to a laboratory line
list, however the laboratory line list still gives robust parameters. We also
find that fixing the log g does not improve the spectroscopic parameters. We
investigate the effects of line selection on the stellar parameters and find
that the choice of lines used can have a significant effect on the parameters.
In particular, removal of certain low excitation potential lines can change the
Teff by up to 50 K. For future HoSTS papers we will use the differential line
list with a solar microturbulence value of 1 km/s, and we will not fix the log
g to an external value.
