How to make complex GUI fit small netbook screen (like when using xrandr, but properly)?

Question

$ pitivi

Does not fit. Huge buttons, huge icons, lot of filler space in UI.

$ xrandr --dpi 45

Now only the font is tiny, but icons and spacers are still huge.

$ xrandr --dpi 90
$ xrandr --output LVDS1 --scale 1.5x1.5

Now better. GUI elements seems to be scaled down to relatively sane size, the font is readable. But the whole things seems blurred/uneven a bit (due to scaling).

How to do it right? How to ask GUIs to pack widgets closer together (like zoomed out), but without that interpolation?