Audit season is only stressful when the year has been left to accumulate. The organisations that get through it quickly treat readiness as a monthly habit rather than an annual project.
First: reconcile bank accounts every month, without exception. An unreconciled bank account is the single most common reason an audit stalls. Second: keep source documents attached to transactions as they are entered, not retrieved from a drawer eleven months later.
Third: close each month properly and do not reopen it. Fourth: maintain a fixed asset register that is actually updated when things are bought, sold or written off. Fifth: document the approvals — who authorised what, and on what basis.
None of these are sophisticated. Together they are the difference between an audit that takes two weeks and one that takes two months.