Rehab - how do you know when enough is enough

[Lesley Whitley]

When you get into doing a rehab ... whether big or value add cosmetic .... what criteria do you use to know when it is "good enough".  It is so hard for me to hold back on not replacing something, just so it looks newer or more trendy (for example, swapping light fixtures and door knobs when the ones there might be okay .... or wanting to swap all switches and outlets to Decora when the standard ones already there just need to be cleaned real good).  I try to remind myself that its a rental, not my personal home ..... but I want my places to look nice.  So, how do you make the decision on how far to go to earn highest rent but without going crazy overboard.  Any help would be greatly appreciated.