I have been doing regular calf stretches which so far are keeping them injury free. The best one for me is stand with feet approx 12" apart and lean forward and drop fingers to the floor about 3 feet in front of you and then walk your fingers back to your feet keeping legs straight and feet flat on the floor - you can certainly feel it. I usually start feet wide apart and move them in gradually until I finish off at 12" apart.
No doubt stretching is good, the more the better, probably.
But generally to keep muscles and tendon healthy and injury free stretching should be combined with strenghtening. After years of Achille pain and one operation 3 months ago I now do both, stretching and strenghtening, on a regular basis, several times a day every day. Always after some warm up (at least several mins fast walking).