When it comes to 'tweaking' anything, I always start with the quickest/easiers stuff first...it don't get much easier than pulling the outhaul out a little bit and see what happens. Once you've gone all the way out with it, then start on the down haul.

But sail around for 10 minutes between changing settings, so you can see what effect your changes are having, and only change one thing at a time, ie. do NOT pull both the downhaul and outhaul, do one, sail around, looking up at the main, slowly head up until the telltale start to lift, and watch.

Try that a couple times, see what effect the change has made. Then then do the other change, repeat, etc.