If you’ve rotated an object in Tinkercad, you may have noticed that two distinct rings appear around your object -- an outer ring with many fine markings, and an inner ring with just a few larger markings.
By keeping your cursor over one of the two rings while you rotate your object, you can modify the precision of the rotation. Use the inner ring to rotate in increments of 22.5 degrees, or use the outer ring for rotating one degree at a time.
It’s also possible to snap your rotation to convenient 45-degree increments by holding down the shift key as you rotate. This way, you can take an object laying flat on the workplane and quickly orient it into a perpendicular 90-degree angle.