Cutting an avocado can be tricky. I find this way of cutting most efficient and you waste less.
1. Put an avocado on a chopping board.
2. Cut it around and separate it. Take the seed out using a knife. Less ripe it is, more difficult to take the seed out.
3. Put your spoon through the gap between the skin and run it through completely and scoop it up.
5. Cut it however you want to.