The advantage you have here is, complete and utter forthrightness.
Just ask them what they want!
Tell them to write a list of everything they hope they might get, from the little things (stocking stuffers), to their "big" gift (Santa), and anything in between. Pictures, links, colours, sizes, item numbers, the more details the better!
But regardless of what they want, today I want to suggest you let them know when you want to know what they want.
I do my shopping at the end of November. All of it. All in one day. My kids know this. I've done it this way since the dawning of time.
They know that just because it's on their list doesn't mean they're guaranteed to get it. But they also know, that if it isn't on the list, they can be pretty sure they won't!
I send the girls emails, and now, to the boys too, reminding them that I'm going shopping in 5 days and that they need to have their lists in.
Getting their lists is fun! They've usually put a lot of thought into them! When the girls were little they were hand written and taped to the fridge. Now that they're grown they come by email. They're shorter, and these days are made up mostly clothes and household things, but the excitement is still there.
I have a budget in my head for each of them. With this in mind, I look at the lists and figure out which things I'll get them. It keeps it equal among them, and allows me to know when I'm done. I usually start with the things they're most hoping to get and then with the amount that's left I choose from some of the other suggestions. When the budget's gone, I'm done.
Or, you can also try to keep the number of gifts the same. I think this is a good idea when they're small, and don't understand about costs.
The last suggestion I have for you relates to Santa gifts for very young children. Like everything else you need to know what they want, and as early as possible so Santa doesn't disappoint!
What worked well for me, when the girls were little, was to take them for their annual Santa visit as early as possible. As soon as he was in the mall. We'd do their hair, put on their special Christmas dresses, bring carrots for Rudolph and make it a special outing. It was always a sweet day. We'd get to have the keepsake picture out all through December and going early allowed me to know, well in advance, what they had asked him for. Plenty early enough to be sure their Christmas wish could come true.
So that's last part of getting all your gift information together. Next week I'm going to suggest how to shop for it in a way that will allow you to spend the least amount of time out getting everything.
Until then, happy list making!
Other posts to make your holidays a little more jolly!
Christmas Part I, Gift List Planning
Christmas Part II, Gift Ideas