Mix up the textiles. Pairing the nice dressy fabric of the pants with mesh/ leather, can dress the outfit down quite a bit. It's really fun and unpredictable, but it works.
Longer, loose fitting- tops. Nothing says casual like a baggy shirt, so combining a graphic tee/ big sheer shirt with your dress pants can create a perfect outfit for a quick afternoon trip to Starbucks :)
Big cardigan. Any layering pieces that go below your waist, hiding the pant line, break the professional silhouette the pants create. An oversized cardigan with wide sleeves- great choice.
Super casual heels. Go for a fun color, crazy style or outrageous height! Your legs already look fantastic in those pants, adding a couple of inches to your figure will make everything look even better.
Let She know how you style your dress pants casually!