Do Not Think Linerally
One of the bad habits you can get into in playing boardgames (and even in real life) is "linear thinking." That is to see an enemy and attack head long into him because he is there. This kind of thinking can cause you to miss opportunities. To quite literally not see that you enemy has an exposed flank that you could exploit because you are too busy trying to destroy him now where you are in contact.
Whether in a game, or the real world, you need to try to keep a part of your head that is not in the battle now, and to look around. You need to do this not just because you may find a flank of the enemy's that you could exploit, but maybe, just maybe, you have a flank of your own that the enemy can (and maybe is) about to exploit.
Do not focus solely on where the shooting is going on at the point of contact. Keep an eye on the larger picture and see if there is something you can do, to gain an advantage instead of just bulling ahead. And make sure that you are not giving the enemy an advantage to exploit.
Always try to keep a few troops in hand to exploit an opportunity, or to block an enemy's effort to exploit one against you. Keeping a reserve applies at all levels, even down to the platoon. And if you commit your reserve, have a plan to create a new one. When you run out of reserves, you run out of options. You can hope that the next higher headquarters can bail you out with its reserve, but you should not count on it as there are other commanders who may be calling for that reserve when you think you need it most.
So do not think linearly, but be flexible. Always look for a way around the enemy where you can hurt him more than by hitting him where he is strongest. An enemy on open ground trying to get away from your flanking maneuver is easier to destroy than one in his entrenchments being hammered by your frontal assault.
Keep in mind the five "F"s.
Find the enemy.
Fix the enemy.
Flank the enemy.
Fight the enemy
and Finish the enemy.