How to improve myself as a recitation (discussion,lab,tutorial) teacher? This question is related to How to improve myself as a lecturer?. However, being a PhD student, my main teaching obligation is leading recitations, i.e. sessions for groups of ~20 students that take place each week after a lecture and the content of the lecture should be revised mostly via exercises.

If you do not use the term "recitation session", please see a related question:
What is the equivalent of European &quot;seminar&quot; in US universities?

At my university (Charles University, Faculty of Mathematics and Physics, Czech Republic), in the mathematics/theoretical computer science classes, usually you have a 90 minute class where the recitation teacher reminds students of what was said in the lecture, hands out or writes exercises, and then, in shorter blocks, students go through the exercises and one student shows the solutions on a blackboard.

I'm not very fond of this structure and I would like to improve my classes with ideas that I cannot find at my university (where we usually do things the aforementioned way).

Some ideas that I've had in my previous years, which you can judge effectiveness of:


handing out "cheat sheets" containing the entire course notes (with compact proofs) beforehand: usually useful, as lecturers rarely have such compact notes beforehand, but very time consuming.
trying to ask each student how he is faring and offer personal advice: when I was a student, I preferred this model, but it takes a lot of time to go around 20 people and shortly talk to each one; my students (in an exit questionnaire) argued that they want more exercises done per class, so time is of the essence.
allow group work during a class -- this seems natural to me (science is mostly done in groups) but often results in people not being able to perform as well in final exams. Plus I am not yet sure how to allow groupwork so that groups don't delegate the work to the one enthusiastic student in the group.
use text questionnaires through and after a session to find out what students would like; I am very happy with the information in those and will use those in the future but students of one university tend to suggest improvements which they have noticed at the same university (especially where it is expected to go to one university for the 3-year Bc. and 2-year Master's).
filming yourself (as was suggested in the lecturer's question) is definitely a valid option but I feel it won't help me as much with recitations, especially since (I believe) there are not many great recitation sessions publicly available on the internet.
I've taught Biology discussion sections, and trained graduate students to teach. I'm a biology education researcher, so I am familiar with studies that measure student learning in different environments. I'd summarize good teaching as follows:


Find the student misconceptions.
If you are good at your subject, you likely have not struggled to learn it. Your biggest mystery is what do students not understand. Unfortunately, students don't have the meta-awareness to tell you, so you'll need to figure the misconceptions out together, at least for the first run-through of the course.
Show students their misconceptions.
Because students don't know what they don't know, they often feel like they understand material that they actually do not. When you show them they don't understand, they are more eager to fix the problem.
Give students an opportunity to learn.
Your class activities will indeed include a lot of group work, because discussing a problem, asking questions and answering them keeps everyone improving right at the sticky points. The big secret to group work so that everyone stays busy? Groups must be only 2 or 3 students. And you'll be walking around and asking the quiet students what they have figured out, so there is no slacking.


Here is an example of how to make this work. It's copied from an earlier answer of mine.


Look over the problem set the night before, and determine the easy ones from the hard ones. 
When students arrive, tell them to start work on a difficult problem. Plan on giving them 5-10 minutes -- whatever they need until many of them slow down. Walk around as they work and just see how they choose to work. 
After several are stuck, have them get into groups of three and compare their techniques and what they found difficult. 


(note: students hate group work because it is more painful than just listening. Most classes will try not getting into groups, or not really talking, just to see if they can get out of it. A cheerful forcefulness works well on American students)


Walk around again and ask questions like, "Tell me how far you are. Can you show me a part that is difficult? Can you get out your lecture notes and find the section relevant to this problem?" 
Usually at this point you will see a sticky point that more than one student is wrestling with. Now is a great time to pull everyone's attention back to the front of the room and you can work through that problem (or one similar) and answer questions for 5-10 minutes. 
Have students return to the problem and complete it. Then they can do a similar problem on their own to reinforce.  
Move on to the next topic and assign a new, difficult problem.


As you can see, this process shows both you and the students what they don't understand, and provides space and motivation to fix the problem. Because you're visiting the groups, they must produce.  

Things I wouldn't recommend for a recitation:


Making course notes or a study guide. Students should be making their own.
More lecturing
Questionnaires are fine, but again, students don't know what they don't know


We've actually posted an example of discussion work for biology here: http://vimeo.com/33801546