i try to line my upper lashline, and i always do it when going for a full eye makeup.
for the under eye, i never ever line my waterline(too sensitive). iinstead i go with a pencil or a brush under the lashes and line as close to them as possible.
usually i don't line the inner corners, but i extend the liner a bit in the outer corner.
if it's a smokey eye, of course, i'll apply the eyeshadow, then the liner (sometimes khol and liquid liner). each time i line my bottom lid i also apply mascara.
i apply a light coat of UDPP before, it really helps the liner to stay put, and not smudge into a panda eye lol.