Advice from a retired educator
At root most educators are bag people. Go to any gathering of educators and you will see it. Almost everyone is lugging around a bag. You will find the bag stuffed with things like student work, an interesting article we hope to find time to read, a class set of worksheets just in case and random art supplies.
I invite you to join the club and create your own educator bag of tricks. Below is a list of things you might want to have in your bag:
Whiteboard markers
Nothing is worse than arriving at a classroom and not being able to find the markers. Hedge your bets and show up prepared. It will save you a lot of stressful scrambling.
Colored markers
Having a set of colored markers can come in handy if you need to improvise because there was no lesson plan or you finished early.
Golf pencils
Students love to use the excuse of no pencil to get out of doing their work. Regular pencils often disappear at the end of the day, but golf pencils usually end up back in your box.
Nice pencils
New pencils can be used as rewards for students doing a good job.
Glue
Just in case. You never know when this one will come in handy.
Paperclips
These can come especially in handy to clip together class sets of worksheets.
Scratch paper
Students frequently ask for a piece of paper and if you are unfamiliar with the classroom you might not know where to look for one.
Paper can also come in handy if you need to improvise activities.
Class set of worksheets (writing prompts, math problems, etc.)
It is handy to bring a back-up activity in case you finish a lesson early or have no lesson plans. Avoid potential problems with the copier by bringing a class set of worksheets in plastic sheet protectors and having students put answers/responses on blank paper. That way you can collect the worksheets at the end of the period and be prepared for your next assignment.
There are many activity sheets for students at different grade levels available on the intranet – just Google it.