An experiment I've been trying in all three weapons (slight variations for each one, but the heart remains the same.) Hasn't taken up the entire lesson for any students yet, but it's made some large parts. Things like choice of target are left intentionally unsaid because this is meant to be taken as a framework, not just one specific lesson. Interestingly, this started out of frustration on my part with a young foilist who has problems letting go of the opponent's blade after a (too strong) 4 parry and therefore missing many ripostes. Each drill is done standing first and then with light footwork, mostly to ensure balance and readiness on the part of the student. Usual caveats about lesson footwork should apply, but those are a post in and of themselves.

First drill (extension distance):
Coach: Invitation
Student: Hit with extension

Here I am very, very picky on the quality of the extension: relaxed joints, efficient motion, muscle isolation, balance, etc. Once again, I could do a whole post on drills I've been doing to improve extension, but for the most part it's still a problem. Improvement is showing, and I am doing some other stuff as well to keep people interested and lay ground work for later but if they can't do a decent extension, there's not much point of working on anything more complex. I try to get them thinking in terms of the tip (or edge, if cutting) pulling them rather than pushing it in.

Second drill (Advance distance):
Coach: Attack with advance and then retreat one or more times.
Student: Pull distance to make coach's attack fall short, then hit with advance before coach can escape.

Basically, get away and go. Parry riposte can easily be thrown in, as well as actions on the coach's advance (stop hit, attack in prep) depending on what the coach does while stepping forward. There are two big foci here, though: a balanced step and good coordination between the hand and feet. Distance is also a concern, but is not very difficult right now (interesting variations could be done shifting the focus to distance.) The student should be able to make my (realistic) attempt to hit fail with distance, have the balance and hand/foot sync to begin their own attempt to hit with the tip pulling the arm, arm pulling the foot and hit before I am back out of distance. This can also very easily be done with parry riposte instead of get away and go, but once again this is just a basic framework. Common pitfalls for students are poor distance (too close and they get hit, too far and they cannot hit me) imbalance (cannot change direction too quickly or falling forward into their own attack; while I normally wait a bit to add in more complex blade actions I can do so earlier if it helps show the student a problem) failure of the hand/foot timing (hand comes out too late and I'm gone before it comes out, too early and their action falls short or is easily dealt with by parry riposte) and just poor extension quality. Basically, I want the hand starting, then the foot starting, then the hand finishing (the hit) before the front foot comes down. The rest of the advance should follow smoothly. I'm doing this with advance to ensure balance; it's easier for them to hide a balance problem in a lunge (and yes, I know there are ways to check lunges as well, but I'm big on the drill itself forcing them to do things right before I ever have to correct them.) As mentioned, parry riposte is a pretty obvious thing to add to the student's action here once they've got the distance and direction change down, and it's easy to modify this to focus on things like choice of distance and timing for parry riposte, choice of action (PR vs get away go vs AiP) etc, but the thing I'm mostly using it for with my people is to make sure they're making a clean, balanced riposte. We'll get to the other stuff when they can do that reliably. If everything else seems like a bunch of rambling nonsense, just remember that I'm trying to give the student a very small window, and to execute whatever action we're doing with this properly, they have to start at the right time and distance with good technique or they won't succeed.*

Third drill:
Coach: Begins with same advance, but can finish immediately or further down the strip. Same with retreating after attack is over; they can "stand and fight" after one retreat, many retreats, or no retreats. They could even redouble or remise.
Student: Keeps eyes open on first step and responds to coach's distance.

This is where the variations can really come out to play. Basically, it's a simple open eyes footwork drill. The student must still be balanced and coordinated (some touches here look exactly like drill 2 just to keep them on their toes) but must now keep eyes open, especially on the first step of their defense and attack and choose their own distance accordingly. Many, many things could be added here. More combative footwork on the coach's push, forcing the student to disrupt the coach's attack or invite the finish rather than just waiting, tempo changes and blade cues for stop hits, more moments for open eyes prep moving forward and backwards, change of decision during the action, second intention or just many offensive and defensive bladework options. I've played with this a bit and will continue to do so, but I'm curious to see where some other people might drive it.

* This is really the heart of what I'm trying to do, and what I meant by the drill correcting them before I even have to. I want to make sure that they get obvious positive and negative feedback on their actions before I so much as open my mouth, and doing that even with such a simple action requires a high level of concentration for both the coach and the student. It reminds me of something a very excellent coach once told me: Good coaches demand excellence with their cues. Put much less elegantly: If you let your students get away with bad actions, they will learn bad actions and you are harming their fencing.