I use tikz-cd to draw commutative diagrams, and recently needed to draw a diagram of the following form (this is a MWE):
\documentclass{standalone}
\usepackage{tikz-cd}
\begin{document}
$$
\begin{tikzcd}[column sep=-1cm]
& A
\ar[ddd, controls={+(-7,0) and +(-7,0)},
start anchor=west,end anchor=west]
& B \\
& C
& D\\
E(BIG THING) & & \\
& F(BIG THING HERE, TOO)
&
\end{tikzcd}
$$
\end{document}
Sadly, this produces a diagram with strange spacing issues; the output looks like this (never mind the bad anchors of the arrow; I know how to fix that):
Note the large amount of white space on the left side of the diagram (the picture is left-aligned on Stack Exchange). Needless to say, this messes up the way my page looks (the actual diagram I want to draw now does not fit inside the margins because of the space on the left), so I'd like to understand tow things:
Why is this happening?
What can I do how to fix it?
Particular emphasis lies on the second point ;-)

tikzpictureenvironment (tex capacity exceeded error), and hence solutions that only work in this environment are a no-go here. Do you think it would be a good idea to re-open the question, if I incorporate this information in it? Or am I overlooking something basic? – Danu May 12 '16 at 20:16tikzcdcreates atikzpictureenvironment - you shouldn't need an additional one. – cfr May 12 '16 at 20:33\path[use as bounding box] (shape I want)seems to only apply to certain parts of the diagram. I'm not sure if I should ask a new question, or not. – Danu May 12 '16 at 20:52