All your Instas aren't Flickr worthy? That's okay! Turn on this Applet. Use the hashtag #Flickr (or one of your choosing) in the caption, and only those pics will be shared — automatically.
If
New photo by you with specific hashtag
This Trigger fires every time you share a photo on Instagram with a hashtag you specify.
Then
Upload public photo from URL
This Action will upload a new public photo, from a given URL to an image, to your Flickr photostream.
Explore more great ways to automate Flickr and Instagram