My kids have something waiting for them when they walk through the door. They are expected to put away jackets, lunches etc., pick up any papers I've set out at the back of the room, and read whatever I've written on the board. This should have been done when the morning pledge and announcements begin (right after the final bell). They work through the announcements, then we correct whatever they were doing together (about 15 minutes of work). Sometimes it is a penmanship practice; sometimes a few math problems on the board to copy and solve. Sometimes a map to read, etc. Always practice of skills already introduced. They know we will be discussing/correcting together on time and they have to be ready, so they settle in pretty quickly. Once we do a quick correction together, I have their attention and we get started with the rest of the day. It's a constant reinforcement of "class/learning begins as soon as you step through the door."