Dense Page Layout (Figure Placement)

Sometimes it happens that figures are on a page or column by themselves, i.e., there is space for text but no text actually put there. This prevents a dense layout. To achieve a more dense layout, add the following after the includes:

\renewcommand{\topfraction}{0.85}
\renewcommand{\textfraction}{0.1}
\renewcommand{\floatpagefraction}{0.75}

Found here