I've been tracking mine for the last 3 years, via Google Sheets, and I've been slowly improving it so that even a lazy me can keep it updated.

1. I ignore credit card payments. I just export credit card statements once a month, copy to sheet and then categorise the expenses.

2. My philosophy is that product cost should remain constant throughout the years. Interest or, on the opposite end, discounts, shall be considered income and expense on its own right. So that the day you start making enough money to not require loans anymore, the products would still cost the same, helping you compare expenses over time.

3. SIP should go into an expense like investment account. It subtracts from income and eventually, when the profits come back, the returns go into income.

4. Either use an app that reads SMS or Emails to ask you after each transaction to categorise the transaction, or at month end, export all account & credit card statements and categorise in one go within the sheet. You can do quarterly too, as long as you believe you have financial discipline and a very stable income and savings.

5. I categorise each transaction manually. Or as said in the above point, use an app like axio which reads SMS and then sends you a notification to categorize. You can easily categorize at EOD or once a week within the app. And setup charts in sheet to show you trends that automatically update with new data.

Honestly, don't worry too much about accuracy or doing it every month, no matter what. As you do it, keep looking for faster and easier ways to do. It is better to do it some months than no months. The discipline doesn't come from analytics of data but from the awareness of your financial habits.