You can upgrade the freetype2 packages using 1-click-install - here and enable the subpixel option.
Now go to Configure Desktop > Appearance > Fonts
enable the "Use anti-aliasing for fonts" and click on "Configure" button
Enable the checkbox "Use sub-pixel hinting"
Select "Medium" or "Full" from the Hinting style (the best settings is both a matter of taste and depending on your monitor, try the different hinting style options to see what suits you best).