A general grab-bag of tips for using LaTeX, from the days when I still used it a lot:
To add nice headers and footers to each page use the fancyhdr package.
Use glosstex for most acronym and glossary needs.
Use the hyphenat package if you need monospace text (such as that set by the \texttt command) to wrap correctly, with hyphenation marks.
The varioref package provides easy-to-use cross referencing with automatic phrases such as ‘on the following page…’ etc.
To include EPS easily in both latex and pdflatex documents, use the following magic incantation in the document preamble:
Then refer to graphics files, when including them, without an extension. Use epstopdf to convert all EPS files to PDF for inclusion in the pdflatex version of the document.
Use the custom-bib package to easily create custom BiBTeX style files.
The following command produces a new environment which gives a nice way of having an introductory paragraph for each new chapter: