How to set the margins of a page in LaTeX

To set the page margins in LaTeX, use the geometry package.

\usepackage[a4paper]{geometry}
\geometry{top=1.0in, bottom=1.0in, left=1.5in, right=1.0in}

Customize Firefox print margins, header and footer

To customize the margin, header or footer of Firefox print, click on File > Page Setup. Then click on the "Margins & Header/Footer" tab.

Choose "--blank--" to remove any item. To add your own text, choose "Custom". A box will pop up waiting for the you to add your own text.

Click on OK when you are done.