The problem: one has ones own latex macros, but then one needs to approximate
some (AMS) journal style. How does one interpolate?
Here we say something about what goes into
ams classes and styles.

For example, what about the \proof{} macro?

The main point of the TrAMS cls file (tran-l.cls) is the line
\LoadClass{amsart}[1996/10/24]

which loads amsart.cls.
In amsart.cls

we have:

\newenvironment{proof}[1][\proofname]{\par
\pushQED{\qed}%
\normalfont \topsep6\p@\@plus6\p@\relax
\trivlist
\item[\hskip\labelsep
\itshape
#1\@addpunct{.}]\ignorespaces
}{%
\popQED\endtrivlist\@endpefalse
}

This leads to too much space between the Lemma (say) and the proof.
In (for example) my macro file
martinCAPromantheo-macros.tex

I have a \mlem{} Lemma environment, which emulates AMS.
However it does not play well with \proof{} when it ends in an
equation environment -- too much space.