Except when there is a runner on third, the offensive is willing to give up an out in order to move a runner along. The overriding defensive strategy is to make sure you get that out. It's nice to get the lead runner and in certain situations you will try hard to get the lead runner, but if there is any doubt, you must get the out at first.
Along with a team strategy, some positions will some general responsibilities that hold true for many of the bunt defensive plays.
In all bunting situations, the catcher is in charge. He must be fully aware of the ability of his defense to field a bunt and make a quality throw. He must take that into account along with the speed of the runner and the direction of the bunt to determine where the play must go. He has the play in front of him and can see the whole field. It's his responsibility to call out where the ball is to be thrown.
The catcher is the coach on the field and must enforce the team strategy to get an out.
The pitcher must focus on multiple tasks during any bunt defense.
The first baseman must first hold the runner on first and then break towards home as the pitch is delivered. With a runner on first and second, you will want to cheat in on the grass as the play will be made at either third or first, so holding the runner close is not as important.
You will be covering first on all bunt plays.
Watch for the runner stealing second. You must alert the team that the runner is going since the first baseman is charging to cover the bunt.
On a missed bunt attempt, make sure you continue to first, as the catcher may be able to make a snap throw to first and get the runner.