I have three children. Here are my ideas:
~PRACTICAL items. I recently attended a baby shower, and the mother got a $60 newborn sized pink tutu, a big ceramic pig (piggy bank) from an upscale store, and many other expensive but rather useless items. Get items that the mom will really need AFTER the baby is born.
*diapers in a size or two larger than newborn size
*baby Tylenol
*Ora-Jel
*Hyland's Teething Tablets
*Johnson's Vapor Bath (for when they have colds)
*Johnson's Vapor Cream (like a diluted baby friendly version of Vicks Vaporub)
*Diaper rash ointment
*baby wipes
*burp cloths
*bottle brush
*Dreft laundry detergent or All Baby or some other infant laundry detergent
*Totally Toddler stain remover spray (gets stains out of ANYTHING)
*nursing pads and lanolin cream if she is going to be nursing the baby
*a book such as "What To Expect The First Year" or a similar title
If you are more creative, you can find an old basket around the house, and get a basket wrap kit in the craft section of the store. Fill the basket with filler, and maybe put in a box or two of baby cereal, a few jars of baby food, a set of baby spoons, etc. and cover it with the basket kit and a bow.
You can also make a basket for the mom to take to the hospital for the birth: warm spa style socks for her, a magazine for her to read while in the hospital, a hand held massager so that the father or someone can massage her lower back, etc. if she has back labor, a bag of lemon drops to suck on (since many don't allow the mother to eat until afte delivery), etc.
There are lots of things you can do.