Finally, if you’re wondering what’s the best baseline to use, after much dicking about, we’ve discovered that going for something lower (like 11px or 12px) is the best tactic. Whilst this means that most of your elements will be on a double baseline (i.e. normal paragraph body copy might be 16px in font size on a line height of 22px using a baseline of 11px), it gives you more flexibility when determining the margin and spacing of items on your site so you don’t always have to have a large 22px or 24px gap between elements.

In that case, why not use a baseline of 1px for even more flexibility?

Seriously, using half-lines as a baseline must be against the initial idea.. As for the spacing between elements of different heights, you can always adjust the margins (smaller top margin / larger bottom margin, or the other way round) to compensate.