Going Overboard

The macros in htm4l make certain tasks very simple. In fact, they make some things so simple that it's tempting to immediately define macros for everything you can think of. You should probably try to resist this urge. For one, they can make your text harder (for you) to understand. You may also spend more time implementing and debugging your special super-duper macro than you save by using it.

My experience is that the htm4l macros are great for

Keeping a consistent look and feel to a set of pages
Putting html tags onto forms
Generating URLs that will work no matter where you move that image directory
Automatically numbering things
Generating "Click here to return to...." html
Generating Next/Previous/Up buttons automatically
Generating "Last modified by...." html
Swapping between lists and 1xn or nx1 tables
Giving you shorthand ways to refer to URLs
Producing conditional output depending on macros defined in a Makefile, or processes accessed through the syscmd shell macros

You will no doubt find other uses. I have learnt from implementing too many macros. There are cases when an m4 macro is perfect for what you need to do, and there are cases where you are simply wasting your time (and making your text harder to read and understand). You'll have to figure out what works best for you.