I love sunsets.
And right before the sun sets, the sun does that awesome flare thing.
And if you want to fake the sun flare, Photoshop has a super-easy way to add it to any photo.
Open your photo in Photoshop. Make sure you are on your background layer. I tried adding the sun flare on a new layer and it didn't work. Go to Filter - Render - Lens Flare. Drag the point where you want to add the flare, choose your strength (brightness), choose your filter type, click OK.
Flare added on the right, behind the tree.
Flare added to the left, behind the mountain.
Small amount of flare added:
A brighter flare added: