Just leave it be.
Get yourself a hydrometer. Give it a week or two, and take a sample. Three days later, take another sample.
If FG hasn't changed, it's ready. But nothing wrong with leaving it even longer to let the yeast clean up a bit more.
Carboy 1: Maple Wheat Ale
Carboy 2: Munton's Export Stout, modified
Carboy 3: Choco-Caramel Amber Ale