In an ideal world, you will never make a personal purchase with company finances. It is not unusual for owners and directors to make purchases on behalf of the company. These transactions are coded back against the shareholder loan so that there is a clear indication that the company owes you for the purchase.
The accounting process becomes difficult when owners and directors treat the company finances as their own. If you need money to make a personal purchase or to pay personal bills, make sure you write yourself a cheque for the amount you need and deposit that money into your personal account before spending it. The cheques will be coded back to the shareholder loan showing that you borrowed money from the company. At the end of your fiscal year, the shareholder loan account will contain all of the transaction showing where you paid for things for the company as well as the transaction where the company paid you.
Keeping your personal affairs out of the company finances will save your accounting support staff the time and trouble of trying to determine what is personal and what is business related.