Vim: faster way to select blocks of text in visual mode

Question

I have been using vim for quite some time and am aware that selecting blocks of text in visual mode is as simple as SHIFT+V and moving the arrow key up or

Answer 1

It could come in handy to know:

In order to select the same ammount of lines for example use 1v You should have done some modification to be able to use 1v, blockwise or linewise.

Today I saw this amazing tip from here:

 :5mark < | 10mark > | normal gvV
 :5mark < | 10mark > | normal gv

You can also reset the visual block boundaries doing so:

m< .......... sets the visual mode start point
m> .......... sets the visual mode end point