I just got done listening to an episode on "Get paid for your Pad,"  They had a tax guy on there talking about tracking your deductions.  

1. Shoe box of receipts.  (not so good)

2. Spreadsheet (Better but messing and time consuming etc.)

3. Separate Credit card for all things deductible 

I land at number two, and try to save all the receipts in shoe box. I bought my STR late last year so I don't have much for taxes and I don't think my CPA will hate me too bad. But I would like to go the route of number 3. Especially since he said, you can make the decision at the register if this is for the rental or not. Then you could have this learn what items are then supplies or maint ect..
During peak it is easy with my PM buying all supplies ect.. but off season and shoulders we use it every other weekend, we are most of the time using the supplies and the off season guests, Cleaning, toiletries, coffee, etc.. Then it all separate from personal as well not intermixed.  

So... My ask is...  Does anyone use/recommend  a Credit Card that has a way to categorize purchases like this so I can track my expenses this way. 

Also, I still prefer to pay the bill from my main checking account then my separate rental account.  Does this matter?  I don't have to, just prefer.

Thank you.