Programming: This includes choosing the dances you intend to call for the evening. You should also have alternate dances in mind. If a group of new-comers walk into the dance at the break you need to be ready to substitute some easier dances. Conversely if there are more experienced dancers present than you had counted on, you may want to substitute some more challenging dances. In general plan on easier dances at the start to help new dancers join in and get some experience. Increase the challenge of the dances to a peak near the middle of the evening and then bring it down again towards the end of the evening, since as people get tired they won't have as much fun trying to get through complex dances. In general plan on 12 dances for a 3 hour evening.
Teaching: Commonly referred to as the walk-through. Tell the dancers who they will be doing each figure with, what the figure is and which way they should be facing at the end of the figure. For example, "With your neighbor balance and swing, end facing down the hall." Commonly the dance is walked through twice. With more experienced dancers you may only need one walk-through. Very occasionally you may need a third walk-through. If you need more than this then you probably chose the wrong dance for this group of dancers. On the second walk-through do it more up to the speed at which the dance is going to be done. There are many times when a demo can be worth a thousand words. However if you find yourself demonstrating too many figures you may need to rethink the dances you are choosing. If you have a group of dancers demonstrate a figure, make sure you pick dancers who can do the figure.
The kinesthetic flow of the dance is what makes contra dance what it is. The transitions between figures are as important, if not more so, than the figures themselves. The connection and coordination between dancers are very important. One way to help beginners (but perhaps not absolute beginners) to become better dancers is to teach them about the transitions. However you need to balance teaching with dancing. The dancers will tolerate, and even appreciate, a certain about of teaching of style and fine points, but if you try to do too much they will become restless and resentful. When teaching style points and tips on the figures and transitions, do so on the second walk-through. Teach just the mechanics of the dance on the first walk-through. Make sure any style teaching you do doesn't bog down the evening.
Calling: With contras you are prompting the dancers on the next figure in the dance. For most figures this should be done on the last 2 beats of the music for the previous figure. Thus if the preceding figure is an 8-beat figure (i.e. allemande, circle, do-si-do, etc.) you should call the next figure on beats 7 and 8. If the preceding figure is a 16-beat figure, such as a balance and swing or a hey, then you should call the next figure on beats 15 and 16. This can vary and some calls may take more than 2 beats to say and others, "Hey!" for example, may only take one beat. Also, since there are some figures that take less than 8 beats there will be times when the calls need to come in odd places. For example in the figure "circle left 3/4 and pass through", the circle takes 6 beats and the pass through comes on beats 7 and 8 so if you were going to call these separately you would make the call "pass through" on beats 5 and 6. However for most dances you will be fine dealing with figures as 8 or 16 beat blocks.
Emphasize the important words in the calls. Initially make your calls more complete and as the dance procedes pare them down and eventually fade out so the dancers can just dance and enjoy the music. For example you might begin calling "WITH your PARTner BALance and SWING", taking 4 beats and then reduce it to just "BALance and SWING" taking 2 beats, before fading out. When ending the dance don't leave a couple sitting out at the top of the set. Signal the band that the next time through the dance will be the last time when there is a couple out at the top. That way they will get back in and be dancing at the end. If the band wants to be signalled that there will be two more times through the dance give them the signal when there is not a couple out at the top of the set.
Calling squares is somewhat different since you are calling as the dancers are doing the figures instead of in advance of the figure. Also you don't fade out while calling a square, but instead keep calling all the way through.
Structure: While there are several different formations for contra dances (duple and triple minor, proper and improper, becket, etc.) they all have a common structure in that they are all 32 bars (64 beats) in length. The dances go with the music, so the tunes are also 32 bars in length. This usually consists of 2 16-bar phrases known as the A part and the B part, each played twice through for one time through the dance. Thus the pattern is AABB.
Working with the band: You need to confer with the band to work out signals. Common signals are thumbs-up meaning speed up, thumbs-down meaning slow down and one finger held up to signal one more time. This should be done during the B part of the next-to-the-last time through the dance. However some bands may want to be told that there are two more times and some just want to be told when to stop, usually with a cutting motion across your throat. Also make sure you know who the leader of the band is so you know who to signal to.
How long to run the dance: A rule of thumb is that there will be 4 dances in an hour at a contra dance. This means that, given the time between the dances, lining up the set and doing the walk-through, the dances themselves will last about 10 minutes. Early in the evening when people are warming up and later in the evening as the dancers get tired you might run them a shorter time. With an unequal dance it's nice to take note of a couple at the top of the set (the shortest line in the room) and run the dance until they return to the top. This gives everyone an equal opportunity to be active.
Working with beginners: This is a major topic in and unto itself. It makes a difference whether you are teaching a beginners' workshop prior to regular dance, a class on contra dance, calling at a regular dance where there are a large number of beginners or calling at a one-night-stand event. Here are some guidelines I like to use to select dances when calling for beginners.
Caution: Avoid being pedantic. There is fine line between teaching the dancers in order to improve their dancing and nagging them. A caller who is to heavy-handed with his/her teaching or who berates the dancers is a real turn-off. Don't scold the dancers (no matter how much you would like to sometimes.) New dancers have a lot of things to think about and if you try to teach them too much they will be overloaded and probably won't remember what you told them and may become frustrated and not come dancing next time. Sometimes it's better to just let them do their own thing and have fun, rather than correcting every move they make. If you mention a few of these tips each time you call, eventually the dancers will begin to remember them when these situations occur.
Another tip that I learned recently from Martha Tyner is that ALL the women face up and ALL the men face down to meet their first corner and then ALL the women face down and ALL the men face up to meet their second corner.