How to win at chess

Plumber,

What was the time constraints on that game?

Board vision is the ability to see what's going on on the whole board. A good example is a bishop that's protecting h8 with a1. It's easy to not see it. They're just blind spots. I think repetition improves that, and puzzles, as he said. Puzzles often take advantage of the fact that we will focus on the problem in a specific section of the board, and sometimes forget that something may be sitting outside of what we're looking at that nonetheless is just as vital a piece as the other ones that you might be worrying over. Yes, I'm not Nils.

If someone doesn't come across right away it makes sense to study the paragraph for a second so you understand what the actual statement/question is. Call it sentence vision.

The OP's advice is actually very relevant, but it requires realizing what kinds of mistakes to avoid. It's not about playing invincible chess, everyone does things that can be exploited with perfect play at some point. The point is to stop making moves you know are bad. 

Do players make moves they know are garbage at the beginner level? Yes. They know a queen isn't worth a rook, and that putting their rook on a square to be taken for free is a bad idea, yet regularly plays like this fill their games. Why? They aren't paying enough attention to what matters. They look too much for good moves and don't check to see if a move is bad. "Oh look, my game changing attack!" they say. Yeah, hanging your queen will do that. Don't look for the wild stuff before checking the obvious. "Is my opponent really just going to give away their stuff?" Yes, that's exactly what they do. And after they hand you their rook, you give them your queen. Address these basic things, and you will improve immensely at the beginning level. It's the most essential factor to spot, more than openings or advanced tactics, just going "oh, that move hangs the queen, I shouldn't do it" or "that move hung the queen, I should take that." Looking at basic checks and captures from a move or before your own move is huge.

Talking about board vision: Many people (also those players with higher ratings) have problems to understand that rooks and the queen can actually move sidewards and not only upwards (moving upwards is the "normal" direction of the game like pawn moves for example). The threat of a rook on the edge of the board will often not be detected for this reason.

My biggest tip for board vision:

Keep an eye on those sneaky bishops! As said before me it's very easy to miss a fianchettoed bishop. Look for the snipers! 

cool

A guy named Purdy suggested checking every diagonal, rank and file for a square before putting something on that square. This was to be done every move!

He was a famous correspondence player, back when they sent postcards.  Evidently he always had time issues in other time controls.

CJS Purdy was an Australian chess player and writer. He won the world correspondence championship in the 1950's, but he was also an IM and Australian champion is OTB chess. Bobby Fischer considered Purdy one of the very best chess writers,