Here are some LaTeX tricks I have found.

TikZ-cd arrows in TikZ

If you want to style an arrow in TikZ the same way it is styled in TikZ-cd, you can do

\draw [commutative diagrams/.cd, every arrow] (0, 0) -- (0, 1);

You can similarly add attributes, such as dashed:

\draw [commutative diagrams/.cd, every arrow, dashed] (0, 0) -- (0, 1);

QED symbol for theorem without proof

The following command inserts a qed symbol at the end of the line, as if \qedhere was used, and works in any environment:

\newcommand\fakeqed{\pushQED{\qed}\qedhere}