Maybe it's of interest of others beside me to add photos to a ride which are posted on Istagram AFTER the ride. Sometimes hours later.
This is how I do it, with a Garmin, but should work with the phone app too.
1. Record the activity as normal, stop when finished, but do not reset.
2. Make the intagram posts you want to appear with the ride on Strava.
3. Resume riding for a few seconds with GPS lock, preferably somewhere else than the ride.
4. Upload the activity to Strava.
5. Pics will appear
6. Tools/trim and crop the end of the ride. Pictures will stay.
For example this race I did last week, went home, and 3 hours after the ride I checked the action camera's footage on my PC for a few shots, made the Instagram posts from those, added a few seconds to my ride, then uploaded the TCX, and cropped it.http://www.strava.com/activities/123329596
For those happy to edit XML files manually, obviously you can add a dummy lap at the end of the activity.