The object you choose should be one on which you would be happy to steady your mind.
The essential point about meditation is this: to get anywhere in meditation you need to be able to really steady the mind and be present.
That's just all there is to it and it is largely a question of just doing it.
There is an important shift that happens in people's practice when they really make the commitment to developing concentration and follow through with it. Until one does this, not much is likely to happen in one’s meditative practice! If you decide to do a concentration practice, stay on that object like a rabid dog until you have enough stability and skill to let the mind rest on it naturally.
The first formal goal when training in concentration is to attain something called “access concentration,” meaning the ability to stay consistently with your chosen object with relative ease to the general exclusion of distractions. This is the basic attainment that allows you to access the higher stages of concentration and also to begin the path of insight (the third training), so make attaining access concentration your first goal in your meditative practice. You will know when you have it.
So, the essential formal concentration practice instructions are: pick an object (the list above is a great place to begin), find a place to practice
Concentration, The Second TrainingMorality, The First and Last Training
where you are as free from distractions as possible, pick a sustainable posture (it doesn’t really matter so much), focus your attention on the object as completely and consistently as possible for the duration of that practice period, allowing as few lapses in concentration as possible, and learn to stabilize all of your attention on that object. The more you practice and the better your practice, the better you will become. Find the balance of effort and steadiness that works for you. Practice again and again until you can attain access concentration. While this paragraph may seem trite or sparse, it contains the formal instructions on how to begin training in concentration.
Should you need someone to tell you how long to practice, start with 10 minutes a day and work up to an hour or two each day as your life allows. If you can learn to hold your attention completely on your chosen object for even one solid minute, you have some strong concentration skills. That said, you might have 10 hours a day to devote to practice. Don’t let me hold you back! How long it will take you to develop access concentration is dependent upon a number of factors including practice conditions, your natural and cultivated concentration ability, the strength of your drive to succeed, and how much you practice.
Sharpening your concentration may help almost everything you do, and can provide a mental and emotional stability that can be very useful.
Concentration can also lead to some very nice states called “jhanas” and other names. These can be extremely blissful and peaceful. Being able to access these states of mind can be ridiculously enjoyable and can increase steadiness and stability of mind. These are of value in and of themselves and also serve the important function in the Buddhist tradition of providing a disposable foundation for insight practices, i.e.