I love avocados but am so often disappointed with them. It doesn't seem to matter whether I buy the 'ready to eat' ones or the 'ripen on the windowledge' ones - they are either hard and woody, of full of horrid brown speckles when I cut them open - occasionally I'll get one thats delicious and it keeps me hooked. How do you choose an avocado? Should it be slightly squashy, and if I get one thats brown inside does that mean lots of other people have been squeezing it? Perhaps I should be only buying packaged ones or going to a greengrocer's and not a supermarket? Any hints?