Do you mean real board vision. Or online computer vision? Either way, the best way is to play long games on the chosen 'board' and really take your time and try to think about as much as possible on every move. You'll be spending so much time looking at and pondering chess positions you will pick stuff up without even realising it. Should help more things start to 'pop out' at you. Actually I'd probably recommend using a board either way most of the time because it's kinda hard to stare at a bright screen and still think and take stuff in.
Board vision

I play almost every move in every game here, once out of 'book' thus: [I play only turn-based, i.e. no-engines-no-tb-corr, here]
I use the 'download pgn' option to download the pos., then at my leisure set it up on a large physical board [an old 'chess table' actually; also one of 5 1 ft x 1 ft boards in case the chess table is 'taken; by the game where I judge I have to take the closest decision...].
I concentrate on the position, write down candidate moves.
then while doing other work I have a look at the board(s) from time to time; from all sorts of sides, not just both sides :)
finally, on the game I decide I'll move earliest, I concemtrate once again on the priority board (i.e. chess-table) -
decide my move;
write it down on a previously printed/wriiten copy of its FEN [to avoid making that move in the wrong game :)];
transfer the next-in-priority pos. on to the priority board;
log in to chess. com;
make my move.
May be you could try using some of the points from the way I play after suitable modifying/adapting them for your requirements....

Definitely, examine every possible move and then make an assesment as to which is the best move, second best, and so on. It helps to analyze the opponent positions as well. I do it when I play against a software program. However, I have a tournament board set up to play each move so I don't loose any face to face skills.

People mean alot of things when they say board vision. If you mean your physical board vision, move pieces around and do some of your chess study on a real board.
If you mean your ability to see where the pieces can go... a nice exercise for knights is to setup pawns on c3, c6, f3, f6 and then try to "tour" a knight from a1 to b1 to c1 to ... h1 to h2 ... to a2 to a3 to b3 ... to h3... etc without jumping on any pawns or squares that the pawns attack. This drill increases your ability to see their moves instinctively. 5-7 minutes is a reasonable goal for now. As you get stronger, maybe aim for 2-3 minutes--at that point you no longer have to think about how a knight moves--you feel it, you see it.
Ozzie posted an interesting exercise for calculating queen moves. I found it useful, and might try to solve it a second time someday. :)
http://www.chess.com/forum/view/endgames/quotendgamequot-calculation-exercise

I meant the same thig by board vision as likesforest's, but my post did not mention any really important part. :(
Likesforest's post is the one to take seriously.
But IMO the thing about physical boards, moving around pieces, etc. is not irrelevant to likesforest's excellent advice. Speaking for myself; when my board vision is poor [in the sense likesforest focused on in his post and which IMO is the correct sense] , it helps me to have things on a physical board, to move pieces around, etc. I often find that then my board vision comes back..] objective sign that board vision's returned/impreoved - is that I can move pieces around in my head - on an imaginary chess board - automatically or with little effort OR with less effort than when I have not so good board vision ...

Thanks to both likesforests and normajeanyates for some excellent ideas. I think "boardvision" and/or "chessvision" (the ability to "see" what's going on) is one of the most important attributes of the successful chessplayer.
When I started playing chess a few years ago I didn't seem to have it and I wondered if it could be developed or enhanced. Like normajeanyates I have also found that setting up a position on a full sized board and simply looking at it from different perspectives for a long time has deepened my understanding of the various elements of the position. I also have a small pocket chess set which I sometimes carry to work with me and study on my breaks when there's no one to talk to. The more you look - the more you see.
But I also find likesforests method to be helpful in a more general way. There is a book on this idea of setting up various hypothetical circumstances and then systematically changing the aspect of one of the pieces. The book is called "rapid chess improvement". I recommend the method but not the book. The book takes up 122 pages to explain a simple concept which could have been presented in about 25-30 pages or even fewer. But I definetely feel as though my "boardvision" has improved as a result of doing these hypothetical excercises.

Here's a sample of what I described above. But don't put the Kings on the board. (I had to include them in order to set up this position on the display)
Now look at the Rook and the Knight. Without moving the pieces, calculate the squares the Knight must move to (safely) in order to attack the Rook. Put your finger on each square to more firmly implant the vision in your mind. Now move the Knight to e4 and do the same thing. Then move the Knight to d4, c4, c5, c6, d6 in a spiraling manner until you have calculated the attack on the Rook from each square on the board.
Then set up the same position with the Rook on e5 and go through the whole process again. Do this until the Rook has occupied every square on the board.Then replace the Rook with a Bishop and do it all again. Then a Queen, etc. Then replace the Knight with a Bishop, etc. You get the idea.
Yes, it is tedious, boring and time consuming. But it works. I have found it to be a great way to pass time in the restroom. lol

wormrose's suggestion is a great idea. When I was young and had just learnt to play chess; then I used to do those sort of things - wormrose's and likesforest's - say in the tube [london underground train] if I managed seating space; and on long train journeys etc. (and of course in the loo [restroom] :) ) - soon progressed to doing this without a board. [except in the mind's eye of course..]
Not so good at it as I used to be when young; mainly because of tranquillsers I've been prescribed off and on for the last 20 years... that's why I am horrible at blitz now... well not horrible, but wildly erratic. Boardvision comes and goes. [at turn-based here, I decide on moves only when board vision is present, or when I can conjure it into presence - oh I already said this, and how I do it, in my prev post...]

Certain things usually only happen on certain squares (of course the possibilities can increase greatly with the skill of the player). I've heard of at least one GM studying an empty board, and i have even suprised myself at the thoughts that surface without the pieces. I've also heard of GM's playing games with nothing but pawns, although i can find no links to support any of these claims.
The blunders are all there on the board, waiting to be made. - Tartakover
I'm rated 1650.

There are TWO things i do:
(1)
I replay games (fresh ones played by me or master games from the archive) in the analyse option of chess.com
i use self-analasys because for this purpose i am not interested in the "best moves" or the computer generated score.
i reset the board and watch the game for start to end. BUT WITH A TWIST:
as i go through each move i relax my mind and observe the game as a child's cartoon.
i let the story unfold as a plot. in my mind i even give little voices to all the characters (the chess pieces of course!). i try to let my focus be on the borders of the board - trying to engulf the actions as it unfolds step by step.
Any time i am surprised by a move i go back as much as needed in order to edit the script in my mind into a more coherant story.
Then, finally i go back to move 1 and FLIP THE BOARD and repeat the process only now seeing the story from the opposite point of view. the narative changes and the insights are more wholistic.
Again, the focus here is to make sense and expand my ChessGaze in order to develop an intuitive board perception.
(2)
at Lichess.com i try finding partners to play with me the Crazy House chess variation.
crazy house realy punishes you for blundering and manifsting new pawns is a skill that demands board vision.
Hope you find this amusing and helpfull!
P.S: a good practice for avoiding blunders would be that at the very end of your decision making, the last thing you should ask yourself just before moving any piece is "will this be my last step n earth?" - or more specific - if it is a knight i.e - "is this going to be my knight's last step on earth?"
Do you guys know how to increase board vision?