Relationships are a two-way street.
It is only fair to expect a lot from someone you are willing to give a lot to.
Hold another to high standards only if you are willing to abide by at least the same standards.
God also has high standards (be ye perfect), but is also filled with compassion, mercy, and love towards all of us (who will never meet those standards without the atonement of Christ).
You should never, ever "settle," but be sure to be realistic.
The way you judge others is the way you will be judged, so judge righteously.