I have a book called "Simple Meditation" by Anna Voigt. Here are some tips from it:
Meditation is not concentration. It is simple awareness! You simply relax and watch the breathing. In that watching, nothing is excluded.
It talks about relaxing, setting a regular time and place, posture, clothing, etc...but I'll just skip to the attention parts you asked about.
Focus of Attention
Either close your eyes or turn your gaze downwards. Whether your eyes are closed or slightly open, your focus remains soft and directed inwards~unless you are meditating on an exterior object. Whatever the object of your attention, be it the breath, an image or sound, you peripherally notice, accept, and let go of passing thoughts, feelings and sensations.
Letting Go
While meditating, pay attention to what arises in each successive moment and accept all as simply 'what is', always coming back to, and holding, the object of concentration--i.e. the practice of mindfulness. Do not hold on to perceived 'bad' or 'good' moments, but allow moments to pass. Let go of your ego-self. My late father-in-law was fond of the Christian epithet "Man proposes, God disposes."...We are all imperfect beings in an imperfect world ~ and let that go too!
Dealing with thoughts
Do not suppress your thoughts, but when they arise, notice them and dispel them. You can let them simply dissolve, release them in 'bubbles', tell them you are occupied right now, or name them and release them. Be sure to come back to your focus of concentration continually.
I bought this book for $6. It's a really good book. Has lots of different mediation techniques in it such as : breathing and meditation, yoga and meditation, sound and aroma in meditation, visualization and meditation, meditating with color, meditation and movement, traditional meditations, and incorporating meditation into a busy working day.