Here's what we did. It works about as well as anything. We built ourselves a screen door made from 1" chicken wire and used 2X4's.

I made a flap from an old suede skirt from the thrift shop. I folded the hem and used fabric glue so there was a weight to the bottom and then cut two or three slits in it. I found one layer didn't keep all the sparrows out, so I added another, staggering the slits. That worked so well even the chickens took a few days to figure it out... I had to tie up some of the strips until they got the idea. Still get the occasional grackle, but no sparrows and the grackles are only after food, not roosting space. Easy to shoo them out.