Tip #2, Frame Rate, Attributes, and Size

Be aware of the relationship between frame rate, animated attributes, and file size. The SWF format doesn't really care how you've assigned keyframes and tweens in your editing tool; when you export SWF, it stores all the changing values for an object on every frame on which they're changing. Each bit of data is quite lightweight (very roughly 6 bytes per frame for each changing attribute), but they can add up, especially at higher frame rates.

To illustrate the relationship, start with an object that's changing position over the course of 1 second in a movie set to 10 frames per second (fps). The tweening would require only 60 bytes or so--pretty efficient. But change the frame rate to 30fps and re-export. You'll see that the animation is smoother, but the tweening information is now three times heavier. Now trying fading the object over the same period of time. The tweening information doubles in size again. At this point your SWF still is fairly lightweight, but consider the file size required when you create an animation style that varies five attributes over 10 seconds, then apply it to each letter in a 30-letter sentence.

The point is simply that you should bear in mind the file size costs of animating even Flash-native attributes. Luckily, LM lets you vary your frame rate without adjusting the duration of your animations, so it's easy to dial frame rate up and down to trade file size for smoothness, as shown below.