I will make a music sheet with a variable distance between the staffs, so I can write other text between the staffs.
What is the best way to increase the distance?
Type ] where you want to alter the upper and/or lower boundary of the staff and select your values.
This, visually, will do nothing in the editor, but in print preview will demonstrate what you want.
You can then set it to a different value or back to the original later on the staff.