How do you tell if something is symmetrical or asymmetrical from its VSEPR/ molecular model/ Lewis dot structure?

For example: OF2

Question

How do you tell if something is symmetrical or asymmetrical from its VSEPR/ molecular model/ Lewis dot structure?

For example: OF2

abb0t · Answer

Look at the central atom, which in this case is oxygen. Then electrons that it has. Oxygen prefers to have 2 lone pairs electrons, and therefore has 2 electrons that are unbound. Now, look at fluorine, it has 7, which can bind to ONE. 
If you connect the dots, you'll see the molecule is linear. And since this molecule is non-polar (there is equal dipole moments on both sides) is equal on both sides, the molecule is linear.

abb0t · Answer

I hope that makes sense, I'm not the best at actually explaining geometry and binding using VSPER theory.