How can you concentrate better?

I just read an article about how ylang ylang essential oil helps with focus.
I use a blend that has ylang ylang, frankincense, lime, patchouli, and I’m not sure what else. It works well to focus.

I know the problem. I’m capable of losing my concentration very easily. I can read pages without anything entering my brain and have to go back to see what I “read.” I’m an auditory reader, that is, I have to hear the words to understand them. To find out if you are an auditory reader, try humming as you read. The words on the page make no sense if I do that. I find novels with a lot of dialogue are much easier to read than non fiction, particularly social sciences which can be very wordy.
These are things to try:
1. find a quiet place. In college I resorted to a library carrel.
2. Try setting a timer to find out how long you can actually concentrate. Set it a little longer each time to see if you can increase that time.
3. Take notes as you go. This will slow you down, but you’ll get the meaning better.
4. Read out loud when you find something is difficult to understand.
5. Be patient with yourself and allow plenty of time to get the reading down.

Get more sleep.

I managed to graduate with high grades and obtain a PhD despite the fact that I cannot read in an environment where I cannot avoide overhearing other people’s conversations. SInce I have ADD, I lack the ability to filter out many types of distractions. Whenever possible, I would study in an environment where I was not exposed to the distractions that were hard to ignore. If I had to read in the Library, I would wear headphones just to block out these distractions. I would request access to private study spaces if the were available. If the school understands that you face an unusual challenge, they will often go out of their way to help you arrange some accomodation that will ameliorate the situation. Don’t be afaraid to ask for such help. If you can study at home where the environment is more condusive to understanding and retaining what you read, make arrangements to read and study there, even if the school has to make some accomodation that enables you to have a suitable environment where you live.

Use ear plugs or head phones when you are in a public place.
Read the material into a recorder to listen to at a later time, such as when you are eating or bushing your teeth, or driving.
Take notes of relevant phrases or words.

I never could force myself to focus and concentrate if it was metabolically inappropriate.

While in college, I used to routinely fall asleep in my books at the library at night. So I began going to bed at 10:00, which is what my body and brain liked.

Then I would get up at 6:00, have breakfast in the dining room with three other non-communacative souls and read, think, concentrate, focus and write with ease.

To this day, I do best in the morning with an intellectual challenge.

Learn about mindfulness.