1. Learn to move yourself first before starting any classes. It will prevent you from bumping into objects, being stuck in an unknown place or even drowning.
2. Always wear underpants no matter what. You may think that it is just a virtual world, nothing ugly will happen, right? Try to fly wearing a skirt with no underpants. You will know what I mean.
3. Find a private place or a changing room to change your outfit. Trust me, it's a horrible idea to be naked in front of other avis, let alone your own students.
4. Choose a decent AO to wear. You might want to improve yourself with Animation Override but wearing lap dancer AO while teaching will bring you lots of troubles both in SL and RL.
5. Activate your headset. It is easier to control a bunch of avatars using voice than text. But don't let your students use voice chat unless it is necessary to do so. (I got this invaluable tip from my mentor)
6. Relate what you teach in SL with what you teach in RL. It will give the students a better understanding of what they are learning.
7. Write notecards to support your teaching. Some sims are graphically amazing but lack of educational information.
8. Learn to build. Sometimes you need to cutomize your teaching in SL but you cannot get the objects you need. Why not built them yourself?
9. Learn to operate press-o-matic and slide presentation screen. These gadgets will improve your teaching termendously.
10. Join educators group in SL to share knowledge and ideas, learn from each other and get information about educational sims. (Many educational sims are not listed in search menu....surprise! surprise!)
11. Learn to make sculptie, AO and machinima and pass on the skills to your students. These skiils will enrich your students' learning experiences in any subjects.
12. Never click those POSE BALLS, especially the ones with F and M text on it. You don't want your teaching with web 2.0 turns into infidelity 2.0.
Just my two cents.......That's all I can think of right now. I will post some more tips in the future.