Micro-adjust size or position by 0.1 pixel

If you are working on something very intricate that you need to line up perfectly it can be very time consuming and laborious to keep editing the position by .1 of a pixel to get things to fit perfectly

What would be really nice would be a modifier key (perhaps Ctrl or Alt with arrow keys), a bit like 'Shift' does but instead of moving things by 10 pixels it would move them by 0.1 of a pixel