Take a plain T-shirt of either white or pink (or some other pastel color) and either use T-shirt transfer paper or T-shirt paints to write "BULMA" on the front, and if you have the T-shirt transfer paper, try to find a Capsule Corps. logo to go on the shirt too. If possible, put the logo on a plain cap or a jacket. Then, either get a light blue wig or light blue hairspray and put your hair/wig in a ponytail on the side of your head. Then wear shorts and tennis shoes and you're Bulma!
Thanks to Teggo for this great idea.