So, the beginning of any story needs to capture the attention of the reader, so he continues and wants to find out what's happening.
A Confederacy of Dunces starts "A green hunting cap squeezed the top of the fleshy balloon of a head." and gives you just enough to visualize the character yet so little to make you want to continue to read.
What techniques are there to come up with a line to simply capture a reader's interest?