Click on New Debt menu item from the options bar after you have logged in:
You would end up in the page shown below:
Fill up the purpose, which by the way is optional, to indicate what this debt or loan is about then in the details section select the appropriate option for what happened, if you loaned to someone else you select “Someone owes me money” and if you owe someone else select “I owe someone money”, fill out the details of the person with whom you had the interaction, the amount with the correct currency, the date and any additional notes for example how you wish to settle the debt later. Click on save and this transaction would show up on the My Friends page.
So there you go you have one less item to track.