It is important that you are committed and consistent with your practice. Like weight training, you can only expect to receive the desired results if you are persistent with it.
Muscles do not instantly grow after one session in the gym, your relaxation muscles of the mind will require that same kind of training.
Here are some steps to stay regular with your meditations:
1) Choose the same time of day to meditate every day. It is easiest to remember to keep up with something when we make a regular habit of it. They say it takes 21 days to make a habit, so accept that in the beginning you may feel a little resistance. Choose a time of day that you know you will be alert for. It doesn't always have to be the same time, but if it helps you set up a schedule it is worth it :)
2) Set an alarm. In the beginning whilst you are making it a regular part of your routine, you may benefit from a reminder. The best kind of reminder would be an alarm clock that goes off to alert you to go and meditate. You may find that you could even benefit from having an accountability buddy, someone who is also getting in to the practice.
3) Plan around your meals. You will probably find that you want to meditate before meals, or a long time after them. When we are busy digesting foods we can get distracted by the churning in our guts.