Tap on the mass airflow sensor while the car is running at idle, tap on it pretty hard like you are knocking on someones door.

Sometimes the idle will change drastically, if it does fluctuate noticeably, that is a real good indication th emass airflow sensor needs replaced.

Is the check engine light on?
You can get your check engine light diagnosed free from most large chain auto parts stores like advance with no obligation of repairs.

Your motor mounts also may be plain worn out causing the engine to feel rougher than it should.

When you start the car up do you feel a semi violent rumble in the drivers seat?

This is usually an idication of worn or broken motor mounts.

Any more issues, send me a P/M and I'll try to walk you through it.