A while back I threw some baby showers - here are some ideas for you, if you want.
Take ANYTHING mom already has for baby's room if it matches the decor of the party (make things easier on yourself and plan the color scheme of the party around the baby's room).
Also borrow any clothes that baby has already been given that match the theme and any gifts that you will be giving and hang them up as decorations. Two birds with one stone!
miniature marshmallows cut diagonally & rolled in colored sugar make great flowers on cupcakes! just adhere with frosting. you can make your own colored sugar with sugar and food coloring - organic sugar makes more "natural" colors. white sugar makes bright colors.
a chair and ottoman as a gift from family members - add a bow and it is the perfect place for mommy to sit and open presents.
Cupcake display - flowers everywhere!the mums are inexpensive in the autumn and simply potted and wrapped in pink tulle.