Samadhi is a form of meditation that focuses attention on an object. The object could be an actual physical object, a sound, an image, a mantra, or just about anything else. Pick an object and begin by taking a few deep breaths to relax. Notice the object in as much detail as you can, but avoid making any judgments about it. Take in every aspect of the object and simply appreciate it. You may find that maintaining concentration on the object is challenging. Every time you notice that your attention has drifted, be patient and redirect your focus to the object. Start with just a few minutes and progress into longer periods of time.
Anapanasati is Samadhi focused on your breathing as an object. Breathe normally through your nose and pay attention to your inhalations and exhalations. Try to find a spot where your breath is the most noticeable. This may be your chest, belly, throat, the tips of your nostrils, or elsewhere. Follow your breath as it moves in and out. You may want to try counting your breaths (1-10 and then start over). You may also want to name your inhalations by saying to yourself, "In" and name your exhalations by saying to yourself, "Out." If you use counting or naming, use them as tools to help you maintain a focus on your breathing. Do not let them become the object of your focus. With practice, you may no longer need these tools.