Ready for another tip?
Generally speaking, panels are written as static images. There is no way to show movement in a comic book. Images usually gain the illusion of movement through the collection of panels, with the “movement” happening between the borders of the panels. This is called “gutter time”. But there is another way for images to gain the illusion of movement within the panel borders themselves. This is what is known as “ghosting,” and it's a technique that can easily be overused.
Ghosting happens when you want to show a character in multiple places within a single panel. This is usually seen in superhero comics, with speedsters such as Quicksilver and the Flash, or those who are very acrobatic such as Spider-Man and Daredevil.
Ghosting looks just as it sounds: a character appears in several places within a panel, dimly/translucently colored, generally showing a path of some kind using motion lines to get to the present where the character is correctly colored/no longer translucent.
This isn't a technique that should be often used by regular characters. By that, I mean characters outside of superhero comics. It can be better used for comedic moments than for dramatic ones, but it definitely can be used for such purposes.
Again, use this technique sparingly outside of superhero comics. Overuse can cause it to lose impact.
When writing the panel description, simply tell the artist that they should have the character in multiple locations in the panel, doing this or that, and where the character should finally end up. It's quite simple, and doesn't need to be extremely detailed. You don't need to tell the artist what the character is doing at every “stop”, although you could. I'm all about both simplicity and clarity when it comes to scripting, and both can be achieved when ghosting a character. Something like a list of what the character is doing within the panel can get the point across without using too many words. Simple.
And there's your tip.