I keep pretty detailed records.

I have a spreadsheet recording each bet for each sport, plus the totals.

I record the date, the team, the line (if it has one), the price, the recommended price if it's from a tipster, the bet in $, the bet in units (if I don't flatbet), the profit in $, the profit in units, if the bet wins, and the cumulative total, plus where I placed the bet. I also have a graph for each sport.

I also have a spreadsheet which lists a ytd for each source of picks, listing profit, turnover, ROI & growth. This is just for quick reference.

I also have a spreadsheet with a calendar where I list the profit for each day and give weekly totals. Days are automatically highlighted green or red depending whether I profied or not. Same for weekly totals. It also has a graph which updates weekly.

Also hav a spreadsheet for keeping track of bonuses, and another one listing all my transactions.