The best way to maintain curl or wave in hair is to perm. As perms have greatly moved on and are kinder to hair than ever, they leave the hair in good conditon requiring less need for gunk to maintain and hold the body.
Having said that, if you want to try blow drying your hair slightly, and incorporating some Charles Worthington mousse or John Frieda (lurrrvvve his gear) products and set on big chunky rollers. Leave to dry naturally. Spritz with laqour before releasing the curlers and tease gently with your fingers.
Other than that, use a hot air rolling brush.
Either of the last two will only last as long as your hair allows it to hold.
Goodluck our wench