It’s possible to pin up to nine key conversations to the top of the Messages app, making them easier to access in a snap.
Just long-press on the conversation you’d like to give more prominence to and select Pin from the menu. That conversation will now appear as a round thumbnail at the top of Messages whenever you open it up. If you want to demote a pinned conversation, simply long-press the icon and tap Unpin to reverse the process.
To add or remove multiple pins at once, tap Edit in the top left and then Edit Pins. You can also press and drag to rearrange them from this mode.
Custom icons
These pinned icons look especially good if you have custom graphics set for your chosen contacts.
Tap a contact’s name at the top of their message thread and press info. Press info again from the pop-up screen, and then hit Edit when their contact page comes up. You’ll see another Edit button appear beneath their thumbnail graphic at the top of the screen.
Tap this, and you’ll be able to choose between custom Memoji faces, standard emoji icons, photos from your camera roll, or customized initials. Looking good!