I'm trying to fill an object with symbols, but can't get the right effect and spacing that I want with the Scatter Brush tool. Is there a way to fill this object with a symbol that would fit them all side by side (hopefully even with the ability to adjust size and rotation for each iteration) without having to tweak the symbol's settings, as well as the Scatter Brush settings? It just feels like that's a lot of tinkering and I might be missing an easier way to do this? Thanks! =)
The easiest way is to use a pattern, which you can then use as a normal fill. You can either go to Object → Pattern → Make or simply drag the shape or symbol to your swatches panel. Double click the swatch to bring up the pattern options with a nice preview, you can change the tile type, and dimensions to easily set up your spacing:
Another option which may or may not be any good to you; use a few transform effects.
Go to Effect → Distort & Transform → Transform to add your first transform. You can get some interesting effects (using the reflect options, for example), the import part though is to set a number of copies and some movement.
This will get you a single row or column:
You can then add a second transform effect to get your extra rows:
I think the best way to achieve what you are trying to do is to create a pattern using whichever symbols you want to put inside the shape and then apply that pattern on the shape's fill. Doing so will let you have a better control on the spacing and distribution of the symbols.