You can find options for the project-wide appearance and position of ornaments and trills on the Ornaments page in Engraving Options.
The options on the Ornaments page allow you to change the position of trills relative to accidentals, noteheads, trill extension lines. You can also change the default appearance of trill marks on subsequent systems, the appearance and restatement of trill intervals, and set the minimum distance between ornaments and the staff and noteheads.
There are musical examples for many options to demonstrate how they affect the appearance of your music.