I cut stalks and anything unsightly. If I see they're sinking into the soil I build them up. I've tried growing corms (glads and crocs) in the thick of iris clumps to take further advantage of the foliage to no avail. Shade? I might transplant some healthy "up and running" specimens this year? I've grown crocosmia directly behind irises in the past and the view from a distance would easily fool anyone that didn't know what they were looking at...
With that said, in mixed beds I enjoy iris foliage throughout the season.