Select your golf course and tap 'Start Round' to open the Round Setup screen.
If you scroll down a bit you'll find the option '+ Add Player'. You can add players from the Hole19 App, from your Contacts or create new ones from scratch by tapping the 'Add Player blue button' (bottom-right).
To add a new buddy, fill in their details and tap the 'Check Icon' (top-right) when you're done.
Players added manually (from scratch) will be saved on the 'Buddies' tab, and you can select them in your next rounds.
Your playing partners will then appear on the 'Round Setup' screen so you can check that everything is set correctly before you start the round.
Note: Email is required to send the round scorecard to your partners.