I'm in the (probably bad) habit of not using <p> to start paragraphs, and using <br><br> to get a line space between them. I also use <br> after a image to put a line of text directly underneath it, and use <br><br> or more <br>s for vertically spacing images. (Such images being non-divved.)
In strict DTD, what are the alternatives to <br>? A string of <p></p>s doesn't seem to have much effect, and I can't say I fancy the cumbersome <div><br></div>!