Principal Repayments
You can set up your loans to pay interest payments and repay debt on a monthly basis. The obvious advantage here is that you are consistently reducing your debt. This is a good policy as long as your cash flow allows it.

Interest Only Loans
As simple as it states, interest only loans mean that you arrange to only pay interest on your loans and make no debt reduction payments.

Lump Sum Payments
With lump sum payments, you can set your loan to an interest only basis and when cash flow is good you can make principal repayments, thereby reducing your debt.
To make lump sum payments work for you, you need to have already thought about your interest rate strategy so that you can make these repayments without breaking a fixed term agreement (breaking a fixed term agreement may possibly incur break costs).
You have to consider your position carefully as there is little point making monthly principal payments from an account that is permanently in overdraft. When you do that, you’ll be moving debt from a 6.5% fixed rate to a more expensive 9% overdraft rate.