To pay an agent for something other than a transaction like a BPO, or showing buyers around, etc... go into their agent profile and click the Other Income tab.
Click the + Add Other Income button and fill in the details.
Click the Save button and you'll see the item added to the Other Income list:
From here you can either Mark as Paid if you're cutting the agent a check, or click the $ Pay Direct Deposit button and pay them electronically.
This income will be tracked towards the agent's 1099s.
The agent will be able to see their outstanding and paid income in their agent portal as well.