I've only had my Ender 3 for a week or so now. I haven't had too much stringing issues so far. You might want to try a temperature test print. Dropping the print temp a few degrees tends to help with the stringing quite a bit in my experience. Definitely turn combing on if your support structure and/or infill is giving stringing issues. I don't think I really did much to my retraction settings. The only major stringing issues came from not having combing turned on and getting major stringing coming from travel between the support material.