What to Look For
- Most avocado varieties remain green when ripe but Hass avocados turn purplish black as they ripen and soften.
- Avocados are mostly sold hard and unripe so when you buy them, allow a few days at room temperature to ripen and soften.
- Select a heavy fruit with unblemished, unbroken skin.
- The fruit should yield to a gentle pressure but if your fingers leave a dent it means it’s overripe. Overripe avocados may be mashed but will soon have unusable blackened flesh.
- Ripe avocados will keep in the fridge for 4-5 days. Storing avocados longer at cold temperatures causes discolouration of flesh and unpleasant change in flavour.
- For quick ripening: Placed in a loosely closed paper bag with a tomato
myfavouritepastime.com
My Favourite Pastime 
My favorite tip is to remove that little nub at the stem. If the flesh underneath is brown, leave it, the avocado will be overripe. It should be bright green or yellow. -Kat
Thats a good one. I have to try it!
Liz
Great tips !