To make sure your eyeliner stays put all day, invest in a stiff, slanted eyeliner brush (the one pictured is very inexpensive, but I can’t recall where I bought it because I’ve had it forever! Maybe KMart?). I reach for this brush daily.
Take the brush and dip it into an eyeshadow that is either the same or very close in color to your liner. Brush the excess off on your hand and pat it gently over your eyeliner. The shadow will lock it onto your lashline and you’ll look freshly applied all day.