Missing school is not something you want to do on a regular basis. It will just mean more work for you in the future. One of the things you'll have to do is have a plan ready for the person that covers your classes. If they don't have a plan, they'll do whatever they feel like, and you'll have no idea where to start when you come back.

Don't wait till the last minute. If you are starting to feel sick the day before, write up your lesson plan in the event that you are fully sick the next day. If you are sick, you'll have been prepared, and if you aren't you can save the plan for the next time.

Give your kids notice. If it's possible, let your students know you will be out and clearly explain how you expect them to behave for the substitute. Let them know that there will be severe consequences for anyone that give the sub a hard time. Also let them know that you're telling the sub to write down any and all offenders so you'll have that information upon your return.

Don't get too complex. Keep it simple. Your sub will thank you for it. You don't want to have them handle anything that you yourself haven't attempted with your students. Give them a lesson that you know your kids will understand, and that you know the substitute will be able to effectively teach in just an hour or less.

Ask the sub to collect work. Even if the students aren't finished, have them round up all of the papers and put it in a pre-labeled folder so you can have it ready for when you come back.

No busywork. Students hate busywork and subs hate having to deal with students that hate something. Don't put your sub in a position of having to apologize for give the kids something that is obviously just a time-killer. Showing a movie or designing a crossword puzzle are out of the question.

Review, review, review. This simple word is what you want your lesson plan to mostly be. Just have the sub go over things you've already taught. Your students will like the chance of impressing the new teacher with the things they've learned. The slower students will get a chance to have it all sink in, and hearing the same info from a second voice does wonders on retention.

Have emergency plans ready. It's good to have a backup supply of plans available so that you don't have to plan a lesson when you aren't feeling well. These can be of a generic nature so that you can just fill a few course-related topics and you'll be set. Not having to start from scratch can mean all the difference.