Visual mode: o toggle cursor position between the beginning and the end of the highlighting
Visual mode: c-q or c-v enter visual-block mode
Visual mode: g+v start highlighting on previous visual area
Notice the keyl. We always use this key to move right but forget another function that it has - It represents the character under cursor. That is to say, if you want to perform an operation on the char under cursor, we can use l to represent it. For instance, we can use y+s+l+surroundings enclose the char with the surroundings we provided.