Jason Miller recently shared a post about a taxonomy of his magical practice and made the point that regular magical practice is better than doing occasional magic. I agree with him, and find that if anything the occasional use of magic tends to be more reactive, done as a response to a situation, whereas a regular practice is a recognition that magic is lived, not just done for convenience. Magic is lived when you make it a regular part of your life. Jason's also correct in noting that a daily practice can remove a lot of the need for doing reactive magic. From my own experiences, the need to do reactive magic has significantly decreased because a daily practice has helped me recognize my own role in those situations and allowed me to work on those issue and fix so that problems don't arise as frequently.
Like Jason, I'd have to say that meditation is the foundation of my daily practice, and is essential for smoothing my life out, because meditation is what allows me to do the internal work that is used to grind the dross of my life into something better. I do meditation every day because it makes life better, focuses me, and allows me to recognize and work on the issues and baggage I bring to the table. By doing such work, the chaos in my life has decreased because I'm facing the root causes on my own end. Meditation has all been useful for strengthening connections with inner contacts and spirits that I work with.
However meditation may not be what you want to do. There's other practices you can do that can still be part of a daily practice. For example, you could recite a mantra or burn a candle and do some kind of magic with that. Or you could do a magical working like the Lesser Banishing Ritual of the Pentagram each day. When I first started practicing I did magical workings, where I vocalized the names of God and later did energy work with the chakras. Jason also has some good suggestions for daily practice on his blog post.
You can also do more than one practice. I do meditation, but I also do energy work each day. The point is that you are doing something which focuses your magical work and opens you to experiencing the spiritual world each day as a regular part of your practice. By making magic a part of your everyday life you are making it a part of your life, as opposed to just doing it when you really need something. The problem with doing it when you really need something is that sometimes it won't work the way you hoped, because you don't necessarily have the spiritual oomph to make it happen. Daily practice, much like daily exercise is a building up and toning of your spiritual power and it teaches you how to focus it so that when you really need it, the magic comes through for you.