We are setting up a new accounting firm and trying to figure out the "common practice" or best method on onboarding clients that haven't had any bookkeeping done thus far this year. We have a client who is coming to us now, and we are getting them set up with quickbooks. We are trying to input all their info dating back to January till now. 

Other experts in the field say if they are cash basis, then it's easier. For cash basis, simply connect the client's bank account to quickbooks, import all bank statements dating back to January to now, adjust charts of accounts, do some bank rules, add vendors, and reconcile each month individually. Is this the correct way for cash basis? 

For accrual basis with inventory, I haven't really gotten an answer for that. Although my understanding is if they generate less than $25 million, then they can choose to use the cash method, which will be most of our clients. Any help would greatly be appreciated. Than you very much.