How do you treat suspense accounts?

Create Suspense Account-Under "Current Asset". For example, Suppose, Bank Balance shows a receipt of Rs 1000/-, source unknown. So, create a Ledger Account naming Suspense A/c under Current Asset and Pass Journal :

Bank A/c Dr 1000

To Suspense A/c 1000

Later, the Amount can be transferred to the specific head like may be customers or receivables etc. say, if the 1000 is by a customer Abc Ltd. pass the Journal:

Suspense A/c Dr 1000

To Abc Ltd. 1000