Marc, my dear friend, Thanks and I'm glad you are enjoying my step by step.
Before I painted the blue stripes on the sides of trousers, I let the red dry completely for at least one week, than very carefully I painted the blue stripes, to keep it straight I used a clean damp brush to wipe excess on the sides.
Marc, painting in oils takes a lot of patience, it is not difficult one you get the hang of it, oils produce very rewarding results, you are in control of your color mixtures.
My advice to you is to practice..... And always ask questions, that's the way I learned.
Cheers
Roc.