Large angels are tricky!
Expose yourself to as many practice problems as possible. After time, your brain will catch up to your eyes and eventually this will become second nature.
I always try to locate the largest one first (for large angels only); for the really big angels try to find the one that is closest to a line or has the smallest bend - knock this one out first. (not sure if this is recommended by others, but look at the answers and eliminate anything that you can based on your findings)
Next, try to figure out which is the smallest... the rest is up to you, and is standard protocol.
Not sure if this helps, but good luck! Remember Practice Practice Practice!!