Early in the day or the day before jack off your normal method. Collect your juice in an old medicine bottle. You can hold the opening right on your pee hole and collect every drop. Milk it good.
Then before your next session, hold the bottle under hot water for a few minutes. Now you have warmed natural lube for pleasure. It even has a nice sex scent to it.
To be more adventourous, collect two or three sessions first.