Allowable Deductions QBO

I'm very new to QBO. I'm a self employed sole trader. I am not VAT registered so MTD doesn't apply to me just yet.

I have a question about how to get my allowable deductions to appear in my P&L. Specifically, mileage and home office. I've had a look around the community and when anyone has asked this question they seem to be told by QB that these allowance are not supposed to show in the P&L and they are to be deducted manually when submitting your tax return.

I understand that, however, as I said before, I won't be submitting my tax return using QBO for the next couple of years until I need to become MTD compliant. For now, I simply want these allowances to show as an expense in my P&L (as I include them currently on Excel).

Can anyone please tell me the best way to show these transactions? I'm not sure whether to set up a bank/cash on hand account for allowable expenses and then pay the total amount each month to an owner's equity account? Or should I be doing a monthly journal? I'm not a trained accountant and I have virtually zero experience with QBO so I really don't know the best way to show these figures without messing something else up.

Any advice is greatly appreciated.