Do you use nappies for both boys? Could you TT DS1 or switch to cloth?
Call around utility and phone suppliers to see if you can get a better deal.
Sell stuff you don't need (a dollar earned is a dollar saved).
Fill up car on cheap petrol days. Use petrol coupons. Make sure tyres are fully pumped.
Invest in door snakes to keep heat in and drafts out.
If you use an electric blanket, change to a wheat bag.
Have a couple of meat free nights a week.