A few big things I've found to help.
1) Get the wife / whoever you live with in on it with you. It's a lot easier to not eat rubbish if your house isn't full of chocolate digestives.
2) Worst thing people ever do is announce "I'm giving up food / fags / beer" and the first topic of conversation anyone ever has with you is the thing you're giving up. Just eat less and do it on the quiet.
3) Take packed lunches to work. Big packed lunches. Have something like a two finger kitkat or a packet of skips so you don't feel totally short changed (both approx 100kcal – mmm. Kitkat or Special K bar, not a hard choice). Or some of last night's dinner to nuke.
4) Pack up drinking as much as you can. It's a really easy way to cut calorie intake without really noticing it in the form of hunger.
I'd also stop worrying about the sprog. They arrive, eat, shit and sleep, and really couldn't give a monkeys about what colour the "nursery" walls are, what toys they have and whether you're using disposable nappies or not. Main thing is not to drop them on their heads.