How to more evenly arrange 2D tiles?

Question

Unity

Hello. Sorry for the lame question.
How to more evenly arrange 2D tiles? What would they be rigidly attached to a given grid? or at least "stick" to each other.
I tried to use SnapSettings - but it's not the right coat. Of course, it binds the tile to the grid, but only after it has already been transferred to the game map, and there it already moves along its relative grid, which is absolutely inconsistent with other tiles side by side.
SnapAllAxes is also a "wrong coat", it essentially scatters tiles in different directions.
How to arrange a bunch of tiles without endless and tedious manual adjustment of their position? The question seems to be elementary to disgrace, but I have no solution to it.
dug the Internet, YouTube, etc. but didn't find anything useful.
There is one video on YouTube where everything is done the way I need it, but it was filmed on Unity3D 4.xx version, in my 5th such trick for some reason does not work.
my version of Unity is 5.2.2f1
Additions:
1. I draw a tile level map, I place the tiles manually (actually like all normal people).
2. This is not about some kind of program drawing of levels (I have not yet taught the computer to read my thoughts and arrange them automatically), and even more so not about random construction.

Answer 1

The best thing I've seen on this topic is the tutorial Lynda - Unity 4 2D Essential Training.
For now, it's on YouTube. Here is a video:
https://www.youtube.com/watch?v=0VBIc7NZq9E&hd=1
There you need to set the size of the units, such as the size of the tiles in pixels: tiles 100x100 means units 100 pixels.
Then 1 tile is added, the transform position is set to (0,0,0).
And then in the tutorial, the dude holds the V button on the keyboard - he says that this is responsible for Vertex Snapping and manually places the tiles.