I save my reward points so I have them there for the double up promotions (Nectar) for booze at Christmas! I'm almost at £100 in Nectar points now. My aim is to increase my points by, on average, about £10 per month, but this may wane a bit now the My Coupons promotion has ended. If I can get to £140 or so by November when I start to buy bits and bobs I'll be happy.
I also have a £75 M&S gift voucher from buying life insurance, so that's going towards our Christmas food too.
Every year I try to pay for the extras with points / vouchers / cash back etc!