Swipe the Spacebar on Your Google Keyboard to Move the Cursor
Android: Google keyboard contains tons of simple gestures, but you can skip them if you don’t know what they are. For example, if you want to move the cursor, slide your finger left and right over the space bar.
As Reddit user wtmh pointed out, the Google keyboard allows you to precisely move your cursor in a text field by swiping your finger over the space bar. As someone who regularly deletes whole words to correct minor mistakes, this is the messenger of God. There are other slightly hidden shortcuts, like swiping to the left of the delete key to delete entire words. Google should really do a tutorial or something for these gestures.