If you are considering ordering christmas gifts online then the most important thing for you to bear in mind would be the actual date that you should be placing such an order. You should ideally get started early especially so when you need ideas on how to choose the right gifts for your loved ones.
If you already know what you should be getting then it may be necessary for you to order early as you can never guarantee stocks and the last thing that you would want is realize the item that you intended to gift to your loved one, such as the Disney Tsum Tsum no longer exists.
So, get whatever you find helpful for your purposes as soon as you are in a position to do so and this would eradicate worries for you. The other advantage of ordering stuff in advance online is because you can also check your delivery to ensure it meets your needs and requirements and if you do decide to return or exchange it then you will have plenty of time to do so.
Compare this to ordering your favourite christmas gifts at the last moment and you will realize that you will have better choices and opportunities of getting unwanted gifts replaced if you order well in advance.