Find somewhere with as much natural light as possible. If needed, use your flash as well.
You need to be directly above the art work to get the best shot.
Zoom in so that only the artwork is in the frame of the picture. Your beautiful face should NOT be in the picture!
Try to flatten out as many of the folds and creases as possible.
Don’t worry too much if there are ripped or missing bits around the edges, a lot of young students' art (k-2 grade) is not a ‘recognisable object’ so if you have to crop out problem areas you will still have a good representation.
Save your edited image files in .jpeg or .png format using as large a size and as high resolution as you can – you can always shrink images without loosing quality but you can’t make them bigger.
MAKE SURE YOUR LAST NAME IS NOT VISIBLE ANYWHERE ON THE ART OR IN THE IMAGE. Personal security is important!