Brush it straight after you shower in the morning, blow dry it halfway so that it is still wet but will dry faster, and shake it out with your fingers. Wait for it to dry, and then pin back a side of it with a bobby pin. This is what I do every day, I hope it works for you.
(I also use now Unite Boosta spray before i first brush my hair. It helps, but just a little, so it is still optional.)