These are my tips:

1. Meal plan and don't buy anything you think you shouldn't eat.
2. Cut down on portion sizes. Even if you're eating healthily, if you eat too much, you won't lose weight. The first few days are hard, then your body adjusts to not eating as much and you no longer feel hungry.
3. Get a pedometer and aim for 10,000 steps per day. Trying to fit in formal exercise is too hard for me because DP's a shiftworker who works different shifts every week so I can't get into a routine of going to the gym/swimming etc. It's just too hard to plan (for me). So I've been wearing my pedometer instead and if you have a goal, it's amazing how much more incidental exercise you can fit into your day just with housework. Putting clothes away in three different rooms is no longer a drag; it's a chance to get another 1000 steps. If I look like I'm going to be short, I jog on the spot for a few minutes several times per day. Cheaper than buying a Wii! Or I go for a walk around the garden while DD2 is asleep. It all adds up. I've lost almost a kilo in a week just doing that and not by making any changes to my diet.