Please don't feel you have to get into debt just for one day! I understand that you want to get nice things for your DCs - I LOVE choosing presents - but really nobody needs lots. Having pared down the pile under the tree over the last few years I have really accepted that Less Is More.
The problem with catalogues and voucher schemes is that you can end up tied into a particular place for all your shopping, when they don't necessarily have the best prices etc.
How old are your DCs? Honestly this year I would not use anything like catalogues (or at least stop now, if you've already started) and just try for frugality. That way you won't start the year in debt and you can then save a little each payday towards 2015.
The other thing I do is look out all year for things that are just right, in case a bargain appears. But I have to be careful I only get something if it's just right and not just because it's a bargain (for this reason I avoid the Reastie bargain threads even though I know they're great!).
I have lots of wishlists on amazon and add anything that I know people will love, I virtually never buy something straight away, I just keep an eye in case the price drops. And it's a useful frame of reference if there's a sale in a shop - eg at sainsburys the other day I got two items that had been on my wishlist for over a year because I knew the prices were shockingly low.
FWIW my DH's ex has always used catalogues and now my teen DSD REALLY resents her for it. She understands that her mum wants to get them nice things (even though she tells her she doesn't want or need them) but finds it so frustrating because she can see how much money her mum is wasting. They argue about it quite a lot.