Figure won't go half way down page

Question

Hi I'm writing a thesis and my set-up is essentially using my universities template where there's a master .tex file that then accesses \input{Chapter} to make each chapter.

In my chapters the general format is text text text with figures at the end each figure on a separate page with it's caption underneath and all centered and at the middle of the page.

I have one figure that is smaller than the rest and when I use my typical commands Latex puts it on the previous page underneath the previous figure (squeezes it in with caption and all) so to circumvent this I use the \clearpage command but now the figure appears centered but not in the middle of the page. Any ideas?

\topskip0pt
\vspace*{\fill}
\begin{figure}[h]
\centering
\includegraphics[width=.9\textwidth,height=.9\textheight,keepaspectratio]{Fig3.pdf}
\caption[Figure one caption for preamble]{Figure one caption on page it appears.}
%\label{fig:filenameoffigurehere}
\end{figure}
\vspace*{\fill}

\clearpage
\topskip0pt
\vspace*{\fill}
\begin{figure}[h]
\centering
\includegraphics[width=.9\textwidth,height=.9\textheight,keepaspectratio]{Fig4.pdf}
\caption[Figure 2 caption for preamble]{Figure 2 caption on page it appears.}
%\label{fig:filenameoffigurehere}
\end{figure}
\vspace*{\fill}

And my package list is (ever changing) as follows:

    \usepackage{amssymb}
\usepackage{amsthm}
\usepackage{textcomp}
\usepackage{siunitx}
\usepackage{graphicx}
\usepackage{color}
\usepackage{amsmath}
\usepackage{fixltx2e}
\usepackage[square,super,sort,comma,numbers]{natbib}
%\usepackage[]{chapterbib}
\usepackage{fancyvrb}
\usepackage{amstext}
\usepackage{units}
\usepackage{inputenc}
\usepackage{array}
\usepackage{tabularx}
\usepackage{caption}
\usepackage{booktabs,makecell}
\renewcommand\theadfont{\bfseries}
\setcellgapes[b]{-3pt}
\newcommand{\mca}[1]{\multicolumn{2}{c}{#1}}
\newcommand{\mcb}[1]{\multicolumn{4}{c}{#1}}
\usepackage{siunitx}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
%\usepackage{multirow}
%\usepackage{float}
%\usepackage[T1]{fontenc}
%\usepackage[hidelinks]{hyperref}
\usepackage{parskip}
\usepackage{setspace}
\usepackage{float}
\floatstyle{plaintop}
\restylefloat{table}

Answer 1

See, if this is of some help:

\documentclass{report}
    \usepackage{graphicx}
    \usepackage{lipsum}

\begin{document}
    \lipsum[1-7]
\begin{figure}[p]% <--- 
\vspace*{\fill}
    \centering
\includegraphics[width=.9\textwidth,height=.9\textheight,keepaspectratio]{example-image-a}
\caption[Figure one caption for preamble]{Figure one caption on page it appears.}
%\label{fig:filenameoffigurehere}
    \vspace*{\fill}
\end{figure}
\clearpage% <--- 
    \lipsum[1-5]

\begin{figure}[p]% <--- 
\vspace*{\fill}
    \centering
\includegraphics[width=.9\textwidth,height=.9\textheight,keepaspectratio]{example-image-b}
\caption[Figure 2 caption for preamble]{Figure 2 caption on page it appears.}
%\label{fig:filenameoffigurehere}
    \vspace*{\fill}
\end{figure}
\end{document}

I use figure option p and put \clearpage after each figure.