Some people believe that a shrewd player is the kind of player who somehow manages to think about the whole board all the time. While not being that kind of a player myself (still a lover of silly mistakes), I know it for a fact that thinking deeply about everything all the time doesn’t even exist in a shrewd player’s wish list. Count on it.
Apart from words arsenal or strategy (or whatever), the key is knowing where to look, and how to deal with it. Where?: focus on the area(s) where it matters most. How?: find a way to deal with it—with what we have on the rack. The point is: think only as much as necessary. That is: never make a habit of giving too deep a thought, for it will surely wear us out.
Decision making is indeed an art: there are no exact rules. But before we decide anything of consequence, it would serve us good to know where to begin with in the first place. And a sensible start would be the sector(s) of the board where the ‘intensity of conflict’—factually or potentially, is the highest (here, they are indicated by the yellow arrows).
The following three examples (from the same game) illustrate where to look on the board and what follows from there (but the decisions are actually always yours—you kind readers). The first is the easiest, the second is a bit deeper since it has the potential of some heavier consequence (with practices, you can do both of these in a snap, believe me). But we would need more time to think the third over, since the circumstances are entirely different.
As Blue, it’s pretty obvious that we need to dump some consonants here. With what we have on the rack, that won’t be a problem. The board is ‘S-hooked ready’ (yellows arrows).
There’s even an easy alternative (see the white arrow). Word like CHAYS (crossing ARIA and hooking FIDO) will dig some agreeable score. But since the board is quite open and line-J is such a wide-open bingo line, we might want to save the S for a later use and to prioritize on dumping the less favorable letters first. Remember: the choice is always ours.
Now line-A is dangerous, especially the middle area (yellow arrow), because it’s a TWS bingo line. But with this board, a blocking move like LUNE or HUE will [presumably] only block the TWS, not the bingo (assuming the opponent does have one). Moreover, throwing the two [and only] vowels we have for a small score is not very appealing.
A logical alternative (more ‘rack management-wise’) is on the corner (white arrow). Here, we can just use one vowel while making some considerably big score along the way.
Closing in on the end game. But not just yet.
The yellow arrows: Horizontally, the middle TWS is out of the question, for we don’t have ‘O’ to make JO. To the far right, JUNTA can only be back-hooked with ‘S’ (column-15 is in fact a bingo line since the two blanks are still missing).
The white arrow: SANE (TOGAS), while might be good for rack balance, throws the last ‘S’ from the rack. But ENGS (TOGAE) is clearly not advisable because it might be just what the opponent needs to strike with a TWS bingo by giving him the last ‘S’ there is (blue arrow).
Last but not least. Please note that the second quadrant (the upper left area) is indeed still quite open for a bingo (especially those lines indicated by the green arrows).
Now please, make up your mind.
PS: There is in fact a 40-pointer word available. But whether this is the best or not is arguable.