Copy and Paste From Your iPhone
If you see something cool on your iPhone and you want to have it on your iPad, you don't need to message it to yourself. You can copy on the iPhone and then paste on the iPad!
This works on iOS 10 and up, and you need WiFi, Bluetooth and Handoff turned on. In most cases you will have these already turned on, but you can check by going to Settings -> General -> Handoff -> On.
Once you have this on, you can copy something on the iPhone. Wait a second and then tap on a text field and then on paste to paste from your iPhone onto your iPad.