they have little bands, usually elastic that go around the wings. usually they snap on so you don't have to try and slip it over the wings. i have noticed one issue, when the hens go to clean their feathers they try to get under the saddle. if you don't have a huge amount of time to make the saddles you can also buy them either through BYC website or i have also found the same ones listed on ebay.
the roo shouldn't have much of an issue with the saddles. it might lessen his advances on the girls because he can't grasp them as well as he used to. i don't recommend getting any that have red on them. it might cause the other birds to pick on the girl. you can take them off and put them through the washer with no issues, if you use the dryer put it on a low setting so it doesn't dry out the elastic bands. i never noticed having to take them off too much before the feathers grew back, so washing is usually when they are done with it's use.