The 3 P's - papering, painting and picking up. All three cost little and bring good benefits. Sometimes a cheap makeover of the kitchen, like new handles, paint, cupboard doors will work too. Keep it clean, well-kept and uncluttered. Spending big money on remodeling does not pay (usually - some of this depends upon your market) and more often I would urge someone to drop their price instead of spending money to make it more attractive.