You can find options for the project-wide appearance, position, and placement of slurs on the Slurs page in Engraving Options.
The options on the Slurs page allow you to change the direction, style, height, and thickness of slurs. You can also set precise values for the positions of slurs relative to noteheads, stems, stem flags, grace notes, and ties, and change the collision avoidance behavior of cross-staff slurs.
There are musical examples for many options to demonstrate how they affect the appearance of your music.