Rally was originally proposed as a mix between Obedience and Agility. But, most people will say, it really has almost nothing to do with agility. The only agility-like aspects of Rally are the numbered course and the fact that it's timed. Other than that, Rally is very firmly rooted in Obedience. The signs and their performance are all Obedience tasks.
Further, many Rally people have never done agility. They may be new to dog sport, or they may have done obedience or be taking obedience classes. But there is one fundamental way that Rally does relate to agility that many people simply don't think about.
In Obedience, a dog progresses from task to task, with a break in between. Heel on leash. Break. Figure 8. Break. Stand for exam. Break. Heel off leash. Break. Recall. In Obedience, the "between exercises" break time is when the handler can praise the dog, and the dog gets mental and physical time off, even if just for a few seconds. It can be a way to keep the dog relaxed. But it can also signal a mental disconnect, then the need to reconnect as the team moves on to the next segment.
In agility, there are no breaks. You start at the first jump and end at the last, and the rest of the course is a constant flow of multiple tasks. Even on the table, the dog is expected to hold attention and position. In agility, good handlers know to treat the course as a single piece. While novice agility handlers will occasionally handle each jump and obstacle separately, not thinking about the next thing down the line till they get there, that doesn't last long. You quickly learn in agility that if you are not planning two to three obstacles ahead you are not going to be setting an efficient line. And in agility there is certainly no time to stop and see what number you're on, figure out what you're supposed to do there, then do it. In agility, all of the obstacles are well known and trained ahead of time and the handler walks the course until he or she feels confident of what needs to happen to create an overall fluent, fast, efficient, smooth line.
The problem is, too many people treat Rally courses like Obedience with breaks. They heel to a sign, peer at it to make sure they know what it is, sort out the details in their head (reminding themselves that this is the call front with/without a halt, or the spiral with the dog INside), complete the sign, then heel to the next sign and do it all over again. They do not think ahead from one sign to the next, much less about how their speed and line exiting one sign may affect approach and performance of the next. They certainly don't think of the Rally course as a single unit, to be accomplished as one piece. As a result, we see a lot of slow, jerky, and/or hesitant performances. Doing Rally this way is handling piecemeal, and the score and time will reflect it.
In Rally, there are no breaks for praise. The team is supposed to start at the Start sign and keep going until the Finish sign. When you think of it that way, it becomes clear that Rally competitors need to walk and plan their Rally course as they would an agility course. Handling as a single line will produce a much smoother, faster run that is a lot more fun to do and to watch.
The first and perhaps most important thing is to know the Rally rules and signs before entering. Handlers should understand each sign at a glance and have the performance of each sign ingrained so they don't have to actually think about it, and can let their subconscious take over the task. This also means that the dog knows its job. Dog and handler confidence begets smoothness.
If you really know and understand the signs, then your walk through can be focused on pace and smoothness. Walk the course once to make sure you know where everything is and what follows what. Then walk the course with an eye to how the *next* sign affects your line on the sign you are currently performing. How will your exit from the call-front-finish-right carry you to the offset figure 8? How should you pace and angle your jump in order to have a smooth transition to that 270 right? Think ahead. What we learn in agility is that often, a mistake at a jump actually started three jumps prior with a poor cue or a bad line.
Finally, walk the course as many times you can as a complete flowing line. Concentrate on keeping your shoulders back and head up and striding out in a brisk, smooth pace. You have a destination. That destination is not the next sign, it's the finish line.
Like agility, Rally should be a dance between dog and handler moving as a cohesive whole throught the course. Walk and think of your Rally course as you would an agility course, and see how your performance improves.
When you come off the course, ideally you should be able to close your eyes and draw a mental picture of the whole course. Try to see it as a diagram with a continual line from start to finish.