Fortunately, I can not show you a picture :(

I have used a prototyping board (epoxy with single pads), the power lines (vcc and gnd) are wired with
thick copper wire (about 20 awg) and the vcc wiring is routed above the chip to the gnd pin and there they
are placed next together.
Crystal is placed close to the pins (7,3728 MHz) and
decoupled with 33pF which are short wired to GND.
INT0 is pull-uped with 1k and also port0 is pull-uped by 8 resistors of 1k. I kept the leads as short as possible.

I will look if I can place a schematic online....