How can one develop his/her concentration?

It sounds like you're a candidate for meditation. There are many resources for learning about meditation. My introduction was through Lawrence LeShan's book How to Meditate, still available at Amazon. Meditation will teach you how to let the thoughts just come and go. Eventually you are focussed on emptiness. A very desirable space indeed. Absolutely divine. (I've explored it for over 40 years, so I can testify to the effectiveness of meditation.) At the very least, you could try staring at a candle for increasing periods of time, extending your single focus concentration. Or another easy one is to count your breaths. You must be following them to count them, so just practice increasing the number of breaths you can count.  You could time how long you can keep yourself from blinking your eyes, also trying to extend the time between blinks. Another idea that may also help is to repeat a mantra. See how long you can maintain your vocalization and try to extend the practice at your own pace. The most simple and widely used mantra is om, the primordial sound of the universe. Often pronounced aum ("ahh oom"). Two syllables, both  sounded on the outbreath.  Try to extend the time it takes to complete one in/outbreath. You will soon find yourself not only focussed, but relaxed as well.   Another technique I use is to write things down that I don't want cluttering my mind. Write it down, let it go. Cross it off the list when it's done. Of course, eliminating distractions can be very helpful in increasing one's focus. And limiting caffeine and sugar intake, which tend to speed our minds up as well as our bodies.   You could find something new to do that you've wanted to take up for awhile and involve yourself deeply in that. Drums may be good. Beginning something new requires even more focus because of its novelty. Try to increase the time you spend on daily activities so that you may more deeply explore them. In other words, slow down a bit. Enjoy the moment.  Peace.

I used to face the same problem, I tried too hard to focus, but i couldn't; in fact, may a times i realized that i was messing up more. There are many ways to increase your level of concentration, one of the easiest way is to meditate. Meditation: Believe it or not, this helps A LOT! All you have to do is, find a peaceful place and relax by simply taking deep breath. Once you feel that you are free from the "load" or in other words, your mind is thoughtless, start reciting the word, "OM" and stretch it as long as possible. Repeat it. Initially, start with 5 minutes and gradually, increase the time. You will realize that your thoughts are in an order, you can focus for longer period and you can totally control your mind. Moreover, you will be experiencing a change in behaviour too. You will not get annoyed or irritated quickly.

There is a saying, "In order for a child to develop concentration, you have to have something to concentrate on." Our society actually has moved to the exact opposite.  The components of a multimedia, multi-digital world and technology providing constant audio and visual stimulation lead to more ways to compete for attention.  Everything is designed to be digested in every smaller bits or to grab one's attention.  (There are studies about how early computer/television time actually physically rewires the brain, but that's another topic.) An individual develops concentration when there is something that they can focus on that holds their interest.  OR when they are in an environment where distractions are removed. Try to peel carrots- with all the sound and visual off.  First it will be a distraction and a chore.  Then you might actually notice the details of the carrot.  Eventually, if you keep going, you might be able to focus on your own thoughts. To develop concentration on a task- it has to be interesting.  Or you are forcing yourself to develop "good work habits." As a side note- concentration actually burns glucose in the brain, so it is a good idea to take mental and physical breaks that involve movement.

- meditate. - remove distractions (get of the internet, leave your phone outside your study area,...) - ask your psychiatrist for concerta, ritalin or other concentration enhancing drugs - try and concentrate for 5 minutes, then 10, and gradually increase until you are in 'study mode' where you can study for periods of 1.5 to 2 hour at a time. (take breaks after a period, preferably by movement or doing non -mind- occupying tasks like cooking or sports or soldering,...)

you need to: do fitness everyday (you can use http://gym-pact.com to motivate yourself), use Forest app on your iPhone to limit use it while you need to work, use Freedom app on your mac or pc to limit use internet without any right reason do mindfulness everyday use http://stickk.com to stick to your plan eat healthy (even for this you can use http://gym-pact.com) go out with friends 3 times/week read 50 pages of a book everyday

Meditate. Start with short times (~10 min or so), and then gradually ramp up, with the goal being to hit one hour. Being able to focus on a cleared mind and steady breathing, all without moving, for extended periods of time does wonders for overall concentration skills. A suggested starter guide: Go to the bathroom. The need to answer nature's call can be...distracting. Find a quiet space. Sit. Position doesn't actually matter a whole lot, contrary to what a lot of traditionalists will tell you. Just find a position that's comfortable, because the goal is not to move (other than breathing) from this position for the duration of meditation. Close your eyes, and start with breathing. For most, 6 counts in, 6 counts hold, 6 counts out will do. Keep the counting steady. Feel free to adjust counts up or down as desired/required. I generally do ~8 depending on how I'm feeling. Keep doing this for as long as you can (or until a preset timer goes off). Once you get breathing patterns down, you'll find that your mind can often wander. Try not to let it. Pick an object and only think about that object (a lot of people seem to like a leaf or drop of water, for some reason; I favor a small flame). This is, without question, the hardest part, and everyone has different tricks for getting around their whirlwind of thoughts--you'll have to develop your own. Make this a habit. 20 min/day will do. Best of luck, friend!

You can do it with willpower.  Unfortunately, you have been without it for a while.  You have got to get back to fighting your urges.  Being a stay at home mother is a difficult job.  However, getting back to work is more difficult.  Keep striving to build up your willpower.  Without it you can't succeed.

Many of the suggested answers are correct, in my experience. Some not mentioned: Dual N-Back Isochronic tones Creatine Dual N-Back ------------------------ A good implementation: http://brainworkshop.sourceforge.net/ It has been shown to increase fluid intelligence in adults, and to help with ADHD in children (and probably adults, too). I did this daily for almost a year.  Noticed a marked increase in some cognitive abilities, and a decrease in creativity over time, probably due to having more trouble "letting go" and relaxing.  The effects seem to fade after not playing for a period of about 3 - 5 days, for me. Isochronic tones ------------------------ http://iso-tones.com/ (The site looks a little cheesy/hokey, I know.  Some cool stuff, though.) Depending on which tone you choose, you can change your  mental state. Creatine ------------------------ Commonly taken as a body-building supplement, its notable cognitive effects are often overlooked. Gives me more energy, makes me want to clean (weird), and helps me concentrate better at work.  I feel smarter like with Dual N-Back, but without a tangible loss in creativity. Works best if taken with something sugary. ------ Please be careful with these.  Moderation is important.

People concentrate on something when they find it important or interesting. So, there can be two reasons for your lack of concentration. You are nervous. If you do get nervous then there are two solutions. One is to prepare so well that you don't even have to think before writing an answee. Second is to remember that it is not a matter of life and death. Anybody can pass exams nowadays and that's enough. Keep that mentality and you might end up topping. Second reason may be you don't find it interesting. If you try hard enough, there is something interesting in everything. Try to find that interesting. Even the most boring topic must have felt fascinating to the discoverer of it. Look at the topic from his/her point of view. Study with interest and you'll be able to write with interest.