Tips and pointers:
Don't focus too much on making the frame of the fireplace perfect. The trimmings will cover everything. My dad insist that he had to sand it down so everything was nice and flat. I didn't have energy to argue with him so I let him do whatever he wanted.
Get home depot to cut your MDF. Its much easier and straighter. Just make sure to measure first.
Prime first and then paint two coats of white paint. I was too lazy to paint two coats so I only did one coat of white paint so its not perfect but I don't really care. Its good enough for me.
Of course here is a before and after picture:
Not too shabby for under $100.