How do you deal with a tenant constantly asking to make repairs?

[Sam Bhattacharya]

Say you have a tenant who wants you to replace carpeting that is worn but still functional.  Or he wants you to fix a gutter that is old but still does the job.  Or he wants you to paint a kitchen ceiling when all it needs is a cleaning.

The tenant does this type of work himself, so he benefits from doing these things every time you pay him to do them.

What would be your approach to dealing with this?  Where do you draw the line and say "no"?