  Using the Fisher information (FI), the design of neutron reflectometry
experiments can be optimised, leading to greater confidence in parameters of
interest and better use of experimental time [Durant, Wilkins, Butler, & Cooper
(2021). J. Appl. Cryst. 54, 1100-1110]. In this work, the FI is utilised in
optimising the design of a wide range of reflectometry experiments. Two lipid
bilayer systems are investigated to determine the optimal choice of measurement
angles and liquid contrasts, in addition to the ratio of the total counting
time that should be spent measuring each condition. The reduction in parameter
uncertainties with the addition of underlayers to these systems is then
quantified, using the FI, and validated through the use of experiment
simulation and Bayesian sampling methods. For a "one-shot" measurement of a
degrading lipid monolayer, it is shown that the common practice of measuring
null-reflecting water is indeed optimal, but that the optimal measurement angle
is dependent on the deuteration state of the monolayer. Finally, the framework
is used to demonstrate the feasibility of measuring magnetic signals as small
as $0.01\mu_{B}/\text{atom}$ in layers only $20\r{A}$ thick, given the
appropriate experimental design, and that time to reach a given level of
confidence in the small magnetic moment is quantifiable.
