How to "cover" for a weak partner

[DaveASA/FED]

Cajun,
I agree you cover for them, what I want to know, admittedly it is difficult to give an idea as there are several situations that might occur in a 7 inning game....but is HOW do you cover for them? Do you just keep an extra eye on their area of the diamond? Do you talk more to "remind" them what they should be doing? Again what do you actually do to "cover" for them? Some past ways you have or things you can think of that might happen that would allow you to help them out.