You will need
one fairly stiff eyeshadow brush
one medium sized mirror
eyeshadow of choice
eyeliner of choice
Load shadow brush with shadow. Hold mirror beneath your chin, and look down into it. Close one eye, and push shadow - brush pointing upwards - into the line of your eye socket. At this angle, the socket line will be perfectly visible in the mirror. Re-load the brush with colour and do the same for the other eye.
Place mirror at your usual angle, and using the same shadow, colour in your eyelids. Make sure you push the colour well down towards the lash-line. This will be easier if you use the brush pointing downwards.
Check effect in mirror, the line where the shadow stops in the sockets should then be blended - you can use your finger or a blending brush -so that it there is no harsh line between the shadow finishing and your skin beginning.
Line eyes - with either pencil, or matching shadow using a brush - above, below, and inner rim if desired and add lots of mascara.
The trick is the looking down into a mirror and following the socket line - if you go too high up with the shadow, it looks wrong - and also, not using liquid liner, it's far too harsh.
Sometimes I do this without colouring in the lid after finding the
socket line, and it works astonishingly well as a softer, yet still smokey alternative. That's actually my usual office makeup, just colour in the socket line, eyeliner and mascara.