\usepackage{} -- threeparttable, Add Footnotes to Tables, Separate From Document Footnotes

\usepackage[para,online,flushleft]{threeparttable} % Custom captions under/above floats in tables or figures.

%  The threeparttable Package Documentation (PDF).
    
% [para] --Notes come one-after-another without line breaks.
% [flushleft] -- No hanging indentation on notes.
% [online] -- \item tag is printed normal size, not superscript.
...

\begin{table}[]   
\small    % Changes overall font size of the table
    \caption{Table caption.}     % \label must immediately follow \caption % \captionof doesn't work here.    \label{tab:table_label}           \centering    % Centering works and is preferred.  PDF shows the use of \begin{center}    \begin{threeparttable}    % Changes overall font size of the table
    \begin{tabular}{lccccccc}
    \toprule    \multicolumn{6}{c}{Table Name} \\ % 6-column table.        \midrule          & \multicolumn{2}{c}{Column Group 1 Name} & \multicolumn{2}{c}{Column Group 2 Name} & \\ % Blank before the first & allows for a 'blank' column name.  Same with the blank after the last &.  Two multi-columns.
        \cmidrule(r){2-3}    % This gives a mid-rule for the grouped multi-column.
        \cmidrule(r){4-5}
          & Column Name 1a & Column Name 1b  & Column Name 2a & Column Name 2b & Column Name 3 \\
        \cmidrule(r){2-3}
        \cmidrule(r){4-5}
        \cmidrule(r){6-6}    % This gives a mid-rule for the last single column.
        Row Name A\tnote{$\dag$} & Value A1a & Value A1b & & Value A2a & Value A2b & & Value A3 \\    % \tnote{1}, \tnote(a) also work.
        Row Name B\tnote{$\ddag$} & Value B1a & Value B1b & & Value B2a & Value B2b & & Value B3 \\
    \bottomrule    \end{tabular}
    \begin{tablenotes}
        \item[$\dag$]{\footnotesize{Footnote Text for $\dag$.}} \item[$\ddag$]{\footnotesize{Footnote Text for $\ddag$.  {\color{Crimson}This still works.}}}   

    \end{tablenotes}
    \end{threeparttable}
\end{table}

...

This is the only option that didn't interfere with the document footnotes or numbering.  Footnotes appear at the bottom of the table much like an un-numbered second caption might.

LaTeX Thesis Template with incredible documentation and concatenation of files and packages, etc.

latexthesistemplate-2014-07-11.zip

This will take you down the rabbit hole, but it's written more like a choose-your-own-adventure.  You know where you're going and why, and when you get there, it's clear what the next turns are.

There's 63 files in 7 folders, but LaTeXtemplate.tex explicitly states which file is being called from where, so it's easy to pop that one (and any subsequent ones) open to read what's going on.  Yes, I said read as in it's well-documented so you can read most of it in English; you don't have to interpret, infer, and research each term.  In many cases most options are included and documented for each package, even the 'unnecessary' ones, which are commented out.  This makes for easy switching between document styles, for instance.

There's excellent documentation included in a separate PDF that even includes some analysis on compilation time depending on what parts are used and discussion about package incompatibilities and loading orders.

I won't pretend to comprehend it all; it won't immediately run on my computer (it seems to be calling files I don't have, and I've not tried to fix it), but for explanation, this is an excellent resource I'll be saving.

\usepackage{} -- textcomp & \celsius vs. {\textcelsius}

So far the only way I've found to properly insert ˚C is to

\usepackage{textcomp}

...

{\textcelsius} % Note this won't work in math mode.  No different spacing is needed around this.

_____________

{\celsius} % Does not work.
\celsius % Does not work, even in math mode.
\textcelsius % Does not work.

I had previously found an online forum that suggested using $^{\circ}$C every time, but that's tedious, ONLY works in math mode, and had caused some errors.

Spaces Following Abbreviations, and A Cautionary Tale

# 7 on Reed College's Ten Strange Things You Need to Know about LaTeX says:

• LaTeX will always force a slightly larger space after a period, but with abbreviations like etc., an extra space is incorrect. Place a \ character directly before a period that should not have any space, and put \thinspace directly after. For periods after single letters ( E. coli), LaTeX does not use an extra-large space. Thus, to get et al. and etc., write: et al.\thinspace and etc\.,

Do your own testing.  Limits of typesetting on blogger.com mean I cannot show exactly what my TeXshop version produces, and I suspect it has more specific programming included than is believed by that guide. 



\emph{E. coli} et al. etc.,

     % E. coli et al. etc.,  
     % This line looks best overall.


\emph{E\. coli} et a\l. etc\.,

     % Eċoli et alėtc; 
     % This line has has a "dot-c", a "dot-e", is missing two spaces, and has a squished semi-colon.

\emph{E.\thinspace coli} et al.\thinspace etc.\thinspace,  
     % E. coli et al. etc. ,   
     % E. coli looks best here.  Not enough space after et al.  Obvious space after etc. ,

I think I'll stick with regular spaces unless otherwise indicated by the thesis editing officers.