Hi Adam. The appropriate time is before stitching. You use it 50/50 with water in light coats when all forms of coloring are done except antiquing. For antique you apply the resolene first as a resist, let it dry well, antique, let it dry well and then add more resolene. On the suede if it touches it, it will probably peel right off. I apply my leather conditioning after the resolene but some people apply a conditioner first. I hope this helps, Cheryl