I have recently had to think about this for my children - oldest nearly 5.
When I was younger i think everything came from Santa. I don't actually remember. Although all presents had to be with us for Christmas morning.
I asked around at work to find out what they all did and all the variations are amazing! From sending all presents to Santa for him to wrap and bring back (wtf?) or just a stocking to every gift under the tree.
Santa doesn't really sit comfortably with me so I don't actually mention him anymore though the family does and ask if DS has been good for Santa coming or what is he asking Santa for.
This year we have kind of settled into a new tradition. My DH feels strongly that the gift giver should see the kids opening their gifts (where possible) and i agree. This mostly relates to gifts from the grandparents who we'll see on Christmas day. They will benefit the most from seeing their grandchildren opening their thoughtful gifts and i think that's lovely.
Plus it means that the gifts under the tree will be more appreciated I think rather than getting everything at once. It'll be staggered through the day.
This year my children will get 1 main present from Santa and the rest will just be there however i won't be saying it's from Santa unless maybe asked by them.
I can assure you it hasn't affected the magic of Christmas and i think it's much nicer for my children to know that they have a lovely family who have taken the time to buy and wrap the gifts for them that they think they'd like rather than from a make believe character who only comes once a year.