I have tried a lot of food and drinks I have heard can make you concentrate better. But it seems like that I don’t get any placebo effects, even if I believe very much that some food and drinks are helpful.
But I still think placebo is a helpful skill, if I only could learn it.
Is placebo easy to learn, or is it more a giftedness?
Is it anything I can do to learn this, I would like to know.
I would say placebo is more an effect than it is a skill. It’s only when you get an effect from a certain substance/activity that you THINK will help, and then it does. When you know it isn’t really gonna work, I think it’s very very hard to get an effect from it…
Well, thats at least my point of view 
for some reason self-hypnosis comes to mind
there must be some relation to placebo
The problem is that this is things I have read could help, and therefore believed. (Coffee and water is one of them, I tried both every day some weeks, but I didn’t notice any placebo effect.)
I don’t really think you can gain the skill of placebo. If you take something and you don’t even feel placebo effects, most likely you never will. I don’t think I have ever had placebo effects from anything I have ever done though.
How could you develop placebo? By becoming more gullible? 
The problem is that you aren’t supposed to know it’s placebo, or else the effect is lost. I guess some people may experience more substantial results if they lack the intruding sense of doubt that counteracts the otherwise potential benefits of blind faith. Of course, you could always stick to proven induction methods if you’re just to cynical to embrace placebo.
I think you can use the placebo even while knowing so.
For example:
You take a stone and announce it to be your dreamstone.
Whenever you lie it next to your bed, it will help you with dreaming (this is more open than "I will get a LD every time).
Well, you know a stone usually hasn’t got a lot of effect.
On the other hand you know about the placebo, and how it WILL help you if you believe it will. It’s kinda paradox, you got to believe that you believe it.
Perhaps placebo isn’t exactly the right word, but I feel that stuff like this helps a lot with focusing your thoughts.
Another thing would be the “waking up” trick:
For example, if you want to wake up at 3 o’clock in the morning, sit in front of your pillow, think about your intention and then touch the pillow with your forhead three times.
I found this one extremely effective. Of course you could also set your intention without touching the pillow, but I believe that rituals are helpfull, and that is why they are.
tapir
Why?
Once you are informed about placebos and
placebo-effect, you have a wide range
on choices.
Don’t try random placebos like RC’s or
chocolate and so on. Just select one of
them to work - whatever you prefer.
You don’t even need to believe in it to work.
just choose one to work and it will work.
I dont really know why you need to decide
for one method, but it will work then - if you believe or not ! 
You can…if you think you can! 
It’s possible to induce placebo. An univesity teacher told that one of his patients, who suffered of heart problems, had forgotten his pills. So he drank a glass of water, doing like if he took his pill, and the pain disappeared.