1. Transferring items on the debit side such as opening stock, purchases, etc.

Since all these accounts show a debit balance in the trial balance and are all direct expenses, we need to debit the Trading A/c.

Trading A/c   Dr. xxx 
To Opening Stock A/c   xxx 
To Purchases A/c   xxx 
To Direct expenses A/c  xxx 
To Sales returns A/c   xxx

(Being transfer of opening stock, purchases, direct expenses and sales returns to trading A/c)