This guide requires you to (a) be using a iOS device that supports Touch ID (b) have Touch ID enabled and (c) be running iOS 8 or above.
Go to the App store and update your LastPass app. appsto.re/us/hvtwt.i
Login to LastPass if you weren't already.
Here you are in your Vault. Now tap the red LastPass logo in the upper right hand corner.
Toggle "Use Touch ID Verification" on
Now that you've enabled Touch ID in LastPass, you will need to launch Safari and enable LastPass in your browser settings. First tap the share icon in the middle of the bottom of the screen.
Tap "More" in the bottom-most icons.
Toggle "LastPass" on
You can drag LastPass to wherever you'd like in the list by tapping and holding the three horizontal lines.
Return to your browser. Now you've enabled Touch ID in the LastPass app AND enabled the app in your browser settings. You are ready to go. Tap the share icon in the bottom middle of the screen.
Now use Touch ID to authenticate LastPass
Select the credentials you'd like
And your credentials will populate. Now you can sign in.
Now that you're set up, you'll have a convenient login experience whenever you use Safari. Enjoy!