
A closeup of my eye after the pencil eyeliner.
You can actually alter the shape of your eye when you draw the pencil eyeliner on depending on how you want your eye shape to me.
In my case, I want my eyes to look bigger so the middle part of my eye is extended higher so that it looks bigger.
But if you want longer eyes, you should extend the eyeliner to the back more, giving the illusion of longer, sleeker eyes.

When I close my eyes, this is how it looks.
Ideally, you should blend until you cannot see the distiction between the black liquid liner and the Prunella pencil liner.
To aid the blending process, you can employ the use of a black pencil eyeliner but you run the risk of getting smudges after a while. What I usually do is just draw on the line between the liquid liner and the pencil liner till the two distinct lines aren't visible anymore. For some reason, coloured pencil liners don't smudge as easily as black ones do. 0_o

Just repeat the process for the other eye and you're good to go!
This is how it looks like when you close both your eyes.
Lastly, just line your lower lashline with the pencil eyeliner.
I usually just line it halfway. Going all the way in is a bit too scary and animalistic!

There we go! The finished product!
Since my right eye is slightly smaller than my left, I have to draw more pencil liner to even it out and make it look roughly the same size.
Here are just some other photos using other coloured pencil liners:

Minty Green from MAC as well.
(Please ignore ugly face, it was the end of a very long day.)

Aaaand...my trademark purple which is from Silkygirl.
If you want to add more sparkle in the form of eyeshadow, add it above the pencil liner, blending it all the way to your browbone. I only do that for special occasions or during the night coz the eyeliner alone look very heavy already.
Alternatively, you can also put white/silver eyeshadow or eyeliner on the inner corners of your eyes to make your eyes look even bigger. Personally, I used a silver liner from some Japanese brand to do it. Again, I only do it for special occasions or for nights out coz it's a bit scary to have so much makeup on normally. =P
So there you have it! How to make your single eyelid eyes look bigger in a super simple way.
If you plan on trying this out, tell me how it turned out! It gets better with practice I assure you.
=D