I'm going to start by discussing the differences between waterlining and tightlining and I apologize in advance to the friends that I'm about to offend...you'll see.
You have an upper and lower lash line and an upper and lower water line. A lot of you choose to line the upper lash line and the lower water line, but never consider the top water line or the lower lash line.
Where are these mammajammas? I created a super awesome diagram to help...
(ORANGE) Upper lash line: the area just above your top lashes
(PURPLE) Lower lash line: the area just below your bottom lashes
(BLUE) Upper Water line: the area just below your top lashes (think inside your eye)
(GREEN) Bottom water line: the area just above your bottom lashes (think inside your eye)
So here's my biggest peeve on the entire planet (and this is where you might get offended). I CANNOT STAND when women ONLY line their lower water line and do it poorly. It makes me think of middle school when you first start wearing makeup. First of all, if you already have small eyes, you are only making them look smaller by doing this. On top of that, it's almost never set properly so by the end of the day it looks awwwful...something like this...spotty, uneven, rubbed off, racoony...just awful!
If you do it correctly, it really should look like this...which I kind of love
If you are going to choose to only line part of your eye, it really should be the top lash line...you have more options (shape-wise) and it widens your eye.
I general, I am not a fan of super heavy eyeliner without the heavy makeup everywhere else to go along with it...stop it Pam Anderson!
Alright, so those of you that are still reading even though I was kind of a douche...let's talk about tightlining.
A lot of my friends complain that they have too much trouble getting a steady line, so they skip the eyeliner. Tightlining is a great alternative.
Too Faced 3 Way Lash Liner is the best product (IMO - that's what cool kids say instead of In My Opinion) if you are a super beginner, but you really can achieve the same look using liquid, pencil or gel eyeliner. However, you'll want a good soft, waterproof eye pencil (if you decide to use pencil), because your cheap shitty Wet N' Wild is not going to hold up and you might very well stab your eyes out in the process.
P.S. Urban Decay 24/7 Liner in Perversion is my favorite...shit lasts all day yo.
Aaaanyway...
Tightlining: The process of filling in all those little gaps in between your lashes with eyeliner. This creates the illusion of super thick plus lashes.
Even with the simplest upper tightlining, you can see a difference
When I am going to a super dramatic eye, I tightline and line both my lash and water lines...it's truly epic.
Below is a gooorgeous makeup job, but you can see she has not tightlined, the bottom lash in particular is full of empty spots...still a great look, but without tighlining technique applied.
Usually when you see a "smokey eye" look, EVERYTHING has been lined...this chick is fully lined/tightlined
Again, if you have small eyes and you apply this technique, your eyes will seem much smaller...but if you really want a smokey, intense eye look, this will do it!