Something I'm still unclear as to whether it's right or not is when I do the smaller window above the bigger one in a casement.Not sure the correct term but the majority of casement windows have them.Personally,I do all the smaller ones all round the house upstairs then I go back to the start and do the larger window underneath (hope I'm making sense).I've seen some people just wash the casement as a whole but I've always been worried about runs this way.What's the general concensus?