Enter hand scrubs!
Easy and inexpensive, they make a great impression. In fact I have gotten more "thank yous" from moms for this gift than any other. Its useful and pretty!
Here's what you need:
Baby food jars (I have started asking for these on my school supply list. The earlier you ask the better!)
Epsom salts (I get plain, this bag will last you forever)
Avocado or other oil
Lavender buds (optional, but this package will also last a long time)
Big bowl, spoons and measuring cups

You might also want to purchase this awesome creativity by Fluttering Through First Grade... my students loved adding all the details. I purchased people colored construction paper so that they could make the card look just like mom! It also includes the cute gift tag for the jar.
**** Please note that I do NOT recommend the use of essential oils in this craft. I promise the lavender buds are enough. Many oils are not safe for use around children and you cannot account for allergies in students or gift recipients. And heaven forbid they should ingest or get some in their eyes while helping you!!