I decided that we would have some definite rules during our rest time when our day was longer. (Now, we have dismissal at 1:20, so we can make it pretty easily without more than a quiet five minute rest with music after lunch. This is what I did. EVERYONE (and I mean EVERYONE) was expected to get a drink and go to the bathroom before we started. If they asked me later, the answer was a definite NO during rest time. It was a bit chaotic while they got their drinks and went to the bathroom, but I put a time limit on it. (It also goes faster if they all have water bottles somewhere in the classroom. My class has water bottles in colored tubs around the room, so that they can find their own quickly and not have to wait in line to get a drink.) If they weren't done preparing for rest time in five minutes, they had to give up that much time of their playtime, which followed immediately. I also put tubs of books within reach of all of the children. I taught them to get the tubs of books out and put them in specific places. We had assigned spots for their mats. They had to sit in their spots, no matter what. Friends were separated. During rest time, no one was EVER allowed to get up, no matter what. They all had books within reach. I put books on tape on, or maybe CD's. The books on tape (with no one holding the book up for to see the pictures) worked better than anything else, especially if I read them the book and showed them the pictures previously. Active types of songs (the ones that they know movements to) did not work well for rest time, so I really couldn't use ANY of my own music! Lullabies worked well. I set the timer for 20 minutes, and then no one could talk or get up and move around unless the place was on fire or they were deathly ill.
Later on in the year, I duplicated a bunch of random "fun" worksheets with dot-to-dots, etc., and also gave any that wanted one a clipboard and a baggie with some old crayons in it, and a pencil. They were allowed to get only ONE worksheet, and then color on the back when they were done. Or, they could get blank paper. Lots of kids really liked the blank paper best! Even later in the year, we switched to journaling time on the rest mats during this rest time. Again, everyone had a clipboard (I bought them cheap at Sam's club), their journal, and a bag of crayons, a pencil, and an eraser. I just kept a class set of these things for the kids to use only during this time. They were not allowed to get up or get a drink, or go to the bathroom, etc. If they asked me a question, I told them that I was not allowed to answer during rest time- the principal would be mad at me if I did! (They of course, believed this!). I made sure to NEVER answer a question from anyone during rest time, or even acknowledge their pretty pictures or work with a nod! I didn't want them to be trying to get my attention at all, so that I could have 20 minutes of peace. Consistency really paid off. Anyone that was talking or getting up, etc., during rest time, had to sit in time out for the first five minutes of their inside playtime, which followed immediately afterwards. This piece of the puzzle is very important!
I modeled my expectations during this time very clearly with my kids at the beginning of the year. We acted out the various scenarios and what would happen to those the followed my rules and those that did not. This helped a great deal. But the most important thing is to be consistent! And make sure you have assigned spots for rest time. Separating those best friends is very important.