I don't want to share every activity I'm tracing on my Strava. It would be great if you could share only single activitys (e.g.Sigma Ride app has already implemented that).
Set te default privacy to "Me Only" on Strava for new activities, and then make public (or visible to Followers) only those that you really want to share. I do use this option since the very beginning, since I see no point is spamming my followers with a dozen of my activities each day.
Disable the Garmin - Strava link, and manually import only activities you really want on Strava.