How to Clean Leather
My first pick baby shampoo. Used with a microfiber cloth rub with the grain of the leather and it will clean up well. Put one drop of baby shampoo drop in 8-12 ounces of water.
I'm a fan of Saddle Soap. You can buy it Walmart, Target, or order it online. Kiwi who makes shoe polish also makes it for around $4.00.
If your pen leaks, try Rubbing Alcohol. Test a small spot rub it with a cotton ball. Best to use small circles. I have heard that sometimes the stain may come back so you will have to repeat the process,
White vinegar is ideal as a basic homemade leather cleaner. It is perfect for regular cleaning especially when you always put you bag on the floor.
The most important thing is never spray cleaning product directly onto your leather bag. It can leave blotches and marks on your leather.