It's dark outside, the streets are full, and you notice the lack of presents underneath the tree. You've looked at your list, twice, and are debating just taking names off it to make shopping easier. This is the sign of someone that has some serious need of Christmas ideas.
The best ideas are those that are bought for the person, with the person's wishes in mind. People like to know that you pay attention to them, to what they say, and to what they've gone through. Some of the best Christmas ideas are those that recognize what a person has gone through, good as well as bad, or those that will help them get through the next year. You would be surprised at the power a throw able teddy bear has for the right person.
People like things that smell good . Christmas flowers are usually a good idea, especially if the person lacks any decoration in their house, or if the person likes flowers. Keep in mind that not everyone does, but enough do. Keep to flowers that are of the season (such as poinsettias) or will last long past it (such as cacti). Just remember that they should be bright, fun, and easy to take care of. Flowers should bring joy and never make a person fell tired or worried about them. So make sure your present is easily cared of and doesn't need any special skills or additional time taking every day.
Children are easy to buy for; ask the parent if the children need anything, or have had any requests from their children. If you ask them personally, you won't get any decent Christmas ideas, especially as their desires change on a daily basis. At the same time, always be on the look out for the weird and unusual; you would be surprised at the times looking for something interesting gives you an idea for potential gifts.
Friends and relatives are even easier, especially as you should know a lot about them going in. However, pay attention to them, and don't be afraid to have fun (but there are limits on how much fun you should have; bear in mind personal belief systems (paintings don't work for everyone)). Also be aware of needs, and that sometimes an expensive gift can be an actual need as valid as breathing, especially to someone that has had a rough year. And don't forget that personal care items make great Christmas ideas, especially if you can make it a surprise; being told to go somewhere to pick something up and finding that it's a manicurist with a chair filled with Christmas flowers can start the person's year off right.
Christmas should be a season of joy and togetherness. It may sound schmaltzy, but being together at the end of the year should be a reason to celebrate not panic. As a last tip to finding the Perfect Christmas Idea, consider that if this is still causing you stress, that just makes you normal, and that everyone feels the same stress. Failure to perform is always a fear, especially when you know that people will remember it and remind you of it. If you worry about it, it's a sign of your humanity; it's a good sign. Just don't let it get to you; there are far more interesting things to worry about.