By injected humour, or randomised words which don't look even slightly believable. If you need to be sure there isn't anything embarrassing hidden in the middle of text.
Phasellus maximus sit amet dolor vitae hendrerit. Maecenas porttitor accumsan nibh, eget porta nisi semper vitae. Sed ut turpis in felis pharetra blandit ut luctus leo. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.