Introduction: QuickStep operates on a QQSS basis. That is, you will alternate between quicks and slows. One slow = two quick. In music, the beat often corresponds to the slow, so you do quicksteps in the time of one musical beat. Hence, why quickstep is called quickstep.
Frame: Standard. Count: SS-(QQSS). Repeat QQSS.
Leaders and Followers: The exact same moves and timing. But when the leader steps forward, the follower steps back. And, line of dance applies.

Instructions (Leader Perspective)
Start with your weight evenly distributed. You are 45 degrees off of line of dance (Also known as DW or Diagonal Wall). Knees are slightly bent. Pay close attention to toes and heels in the instructions below

The Beginning
When you begin quickstep, you begin with two slows.
Slow1: Your left foot steps forward, heel-toe. The follower's right leg will step backwards. Your legs should currently be parallel to your partner's.
Slow2: Your right leg steps forward, heel-toe, in between the follower's legs. Two things. First, for the rest of the time in quickstep, your right leg will step outside of your partner. But for the first step in quickstep, it goes in between. Second, timing is crucial here, lest you wish to experience bruised knees and stomped feet. If the leader moves too fast, kneecaps are going to clash. If there's no room for the leader to slip his leg in between (as in, the follower left foot crosses behind the right instead of going straight behind), feet are going to tangle. Ergo, communicate with each other to prevent miscues from occurring.

Quarter Turn (SQQS, DW)
When the leader does a Quarter Turn, the most important thing is that your right leg, when stepping forward, steps OUTSIDE.
Slow1: Like Slow2 in The Beginning. But this time, when you right leg goes forward, heel-toe, your leg goes outside the follower's right leg.
QuickQuick: Your left foot comes forward next to your right foot, then step left parallel to line of dance. On the second quick, your right foot steps so that your feet together. On both of these quick steps (and for all quick steps), you are on your toes.
Slow2: Your left leg steps back, this time, as toe-heel. See below for the whole deal on toes and heels.

Chasses (SQQS, Backing DC = Diagonal Center)
Think of this as a quarter turn, but instead of going forward, you're going backwards.
Slow1: Right leg steps backward, toe-heel (of course, there's no way to do this heel-toe. Try it! It's absolutely uncomfortable)
QuickQuick: Left foot slides to right foot, then steps left. Right foot then steps to have feet together. You are on your toes,
Slow1: Your left leg steps forward, 45 degrees to line of dance. This is heel-toe.

Toes and Heels. In quickstep, it is very easy to go "bounce-bounce." That is, because the tempo is so fast, couples bounce up during the quicks and bounce right back down before bouncing up again. This doesn't look good. It is also an indication of lack of control over your movements. Hence, the purpose of toes and heels is to smooth away this bouncing. After finishing two quicks, you are elevated. When doing slows, you are not elevated. So, toes and heels are the way you transition the difference of elevation. When elevated, you come down by stepping toe-heel. If you stepped heel-toe, there would be a jarring change. And when going to elevated, you do heel-toe so you can rise up.

Upper Body: When stepping backwards, your torso faces the same direction that you are facing. When going forwards, keep your torso parallel to line of dance, but nose and toes still face DW. This is so that for moves such as lock step, you can signal by changing the direction of your torso (may or may not be true).

Instructions (Follower Perspective)
Exactly the same as the leader. The only difference is, you never have to worry about your right leg stepping in between the leader's legs. That's a leader thing only. And for quick quick, your left foot is the one that comes to match your right.

Tips and Tricks
  • Railroad Tracks. Imagine a set of tracks parallel to line of dance. When you start quickstep, you are on one rail. The slow steps take you to the next rail, and the two quicks are on the rail. You are simply transitioning between these two rails again and again in quarter turns and chasses.
  • Nose and Toes. Your nose points in the direction of your toes. For leaders and followers, you face the way you are stepping.
  • Weight. Weight should be on the balls of your feet. It's extremely hard to move quickly in quick step (or in any dance) if your weight is spread throughout your entire foot.
  • QuickQuick. One common mistake is that couples often rush the quickquick. That is, before the trailing foot catches up to the front foot, the couple has already moved on. In quickstep, you should always have an instance of time where both of your feet during quickquick are TOGETHER.
  • STOP. You should always maintain balance and control. Yes, you're moving fast in quickstep. That's no excuse for not being able to control your momentum. At each slow or quick, you should be able to suddenly stop and not fall over from imbalance.
  • Tempo. Quickstep is fast. Yet, it's not that fast. It's very easy to rush the steps. So listen to the beat and don't let your feet get carried away.
  • Constant Increase and Decrease. Another way to imagine the idea of toes and heels/railroad metaphor is that you are "up" on the rails and "down" in between. When negotiating the height change, you should be increasing and decreasing at a constant rate.

Advanced Concepts

  • Foxtrot: Quickstep and foxtrot are done together as a group in Silver level and above because they're very similar dances. Note that many things in Fox apply to Quick and vic versa.
  • Hoppity Hoppity Hop Hop Hop: At the upper levels of quickstep, you will transition from what the SSQQ you've learned as a beginner into jumps, skips, runs. I haven't progressed to there yet, but one thing that I have noticed is that when executing those moves, you just have to go because you can't stop.