  Classical novae are eruptions on the surface of a white dwarf in a binary
system. The material ejected from the white dwarf surface generally forms an
axisymmetric shell of gas and dust around the system. The three-dimensional
structure of these shells is difficult to untangle when viewed on the plane of
the sky. In this work a geometrical model is developed to explain new
observations of the 2015 nova V5668 Sagittarii. To understand the ionisation
structure in terms of the nova shell morphology and estimate the emission
distribution directly following the light-curve's dust-dip.
  High-cadence optical polarimetry and spectroscopy observations of a nova are
presented. The ejecta is modelled in terms of morpho-kinematics and
photoionisation structure.
  Initially observational results are presented, including broadband
polarimetry and spectroscopy of V5668 Sgr nova during eruption. Variability
over these observations provides clues towards the evolving structure of the
nova shell. The position angle of the shell is derived from polarimetry, which
is attributed to scattering from small dust grains. Shocks in the nova outflow
are suggested in the photometry and the effect of these on the nova shell are
illustrated with various physical diagnostics. Changes in density and
temperature as the super soft source phase of the nova began are discussed. Gas
densities are found to be of the order of 10$^{9}$ cm$^{-3}$ for the nova in
its auroral phase. The blackbody temperature of the central stellar system is
estimated to be around $2.2\times10^{5}$ K at times coincident with the super
soft source turn-on. It was found that the blend around 4640 $\rm{\AA}$
commonly called `nitrogen flaring' is more naturally explained as flaring of
the O~{\sc ii} multiplet (V1) from 4638 - 4696 $\rm{\AA}$, i.e. `oxygen
flaring'.
