What kind of life is required for practicing Metta?

Here's the quote from Karaniya Metta Sutta : > "This is to be done by one skilled in aims
who wants to break > through to the state of peace:
Be capable, upright, & > straightforward,
easy to instruct, gentle, & not conceited,
> **content & easy to support,**
> **with few duties, living lightly,**
with peaceful faculties, masterful,
modest, & no greed for supporters." So one should be content and easy to support, unburdened with duties and living lightly. According to this standard, what is the best lifestyle for practicing Metta? How can one practice Metta in this [predominantly] materialistic world? Is Metta best practiced as a monk?