You can always share your Instagram photos to Twitter by clicking share buttons on Instagram while posting photos. But That Instagram photograph will shown as a link in Twitter feeds. For example see this Instagram pic which is posted by aslisona (Sonakshi Sinha):
Hi! by @aslisona
This is showing only a link in Twitter as shown in below tweet without an embedded pic.
Go to IFTTT an register an account if not done.
Use the following IFTTT Recipe by giving your respective usernames and passwords of Instagram and Twitter. And activate the recipe.
When you finished your settings on IFTTT, post a photo on twitter and check this on your twitter feeds. Your photo will appear with the same caption as in Instagram with an ift.tt link as embedded photo. Your Instagram Hashtags will also work on Twitter.
It may take a moment to invoke the services to display the pic on twitter. Njoy!
Source: http://www.angraj.in