How do you outline your drawings?
There are multiple ways you could approach outlining your characters. It all depends on your own style and what you want to achieve.
The following link is a free character illustration tutorial by Justin Cook. 34 minutes into the video he goes into inking techniques. If the outline is what you are most concerned with you could fast forward by scrubbing the play bar. Notice his brush settings. The minimum size is smaller than the max size so he can take advantage of pressure sensitivity settings while he draws and vary the line weight by pressing lightly for thin or harder for thick. His technique might save you a bit of time as opposed to manually setting brush sizes for variance. However, if you want a uniform outline then minimum and maximum brush size settings that are the same size may give you a slicker line.
If you’re looking for specific techniques on how to make appealing lines then try the following links. Ignore the fact that the tutorials are for Adobe Photoshop and Illustrator… once you know how to use the drawing tools in Animate you can apply the same principles when dealing with line weight. The articles do a good job at describing what line weight is and offer three different styles.
One thing that you might want to consider: Make sure that you create your characters large enough with a wide enough outline so that the shapes hold up well once you shrink the character down. This might also mean that the lines are a little thicker than you would normally draw with. For example, take a look at the way the Billy and Mandy characters are outlined (do a Google search and look at some close ups). They use a rather thick black line that makes the characters pop out in front of the background even when reused at a smaller size. Also notice that the background automatically recedes because they tend to use colored outlines and fills that aren’t as dark as the black character outlines or base colors.
Also, if you’re using multiple characters in the same project that are of different heights you may want to make a size chart to use as a template with all the characters sketches side by side. That way the outlines on all the characters will be consistent when you’re done inking and placing them in the same scene. Otherwise you could have a short character with an ultra thick outline and a tall character with one that looks pencil thin.
In case you don’t already know this there are tutorials that specifically teach you how to use the drawing tools in Animate II:
Tutorials Pack 3: Drawing, Tracing and Cleaning
I hope that helps.