One's personal practice (sadhana) will vary with each and every person that has one. Mine has a devotional bent to it. So let's start with something simple, like picking some time to set aside. That means actually scheduling some time..
THE 30 MINUTE RULE
I like this rule! 15 or 30 minutes a day makes for a strong foundation for your practice. Whether it's stretching, meditating, running, reading, over the years, it will do wonders for you. But when it comes to city life, it can be tough sticking to a daily routine forever. Soooooo, at times, it can be useful to bend the rule a bit. Since 30 minutes a day roughly translates into 15 hours a month, some combination of weekly yoga classes, time at the gym, long hikes on weekends, monthly retreats, ceremony and meditation, should fulfill your 15 to 30 minute a day requirement. The important part is commitment. Make your choice and stick to it. Sadhana is, in this way, a yoga of self love. This isn't building healthy habits either. Sadhana is a choice, each and every time you do it. It's a choice to devote your time to your cause.
So get started! Baby steps are totally ok. No need to jump in head first unless you like swimming. I'm good with wading around in the shallow end till I'm ready.
My practice seems to revolve around Mondays and new moons. I'll tend to my altar, do some meditation or give some offerings. I'll see clients, work on projects, connect with my teachers, whatever I need to stay conscious of my connection with Spirit. Monthly rituals are sometimes done in private, sometimes with friends and colleagues. Over the course of the week, I try to do some yoga and exercise. I always consider my work with clients to be part of my spiritual practice. That's why I've choosen modalities that have a spiritual bent to them as well. I also try to be in or near "nature" whenever I can. At least once a month at worst. Urban nature counts. If I can't make it to the forrest, I visit the land around me, abridge over a river, the yard, I'll even talk to my plants.
It gives me a sense of connection, a sense of continuity in my life. Especially now that I've been doing it for a number of years.
So where do I start?
Practice just sitting comfortably and peacefully for five minutes. You don't have to cross your legs unless you want to. You don't need to do anything else, just sit. You might find it can be a hard thing to do without fidgeting or thinking about any distraction, or suddenly having to pee. After your sitting, check yourself out. How do you feel? Was it easy, difficult? Did you fall asleep or get distracted by the TV, phone, etc? Continue this practice till you feel good about sitting. Then expand it. Try something ceremonial like lighting incense or a candle each time you do it. Experiment with having your eyes closed or focused on some object( a cross, a mandala, a blank wall, a photo, etc.). Switch when or where you do it or experience it clothed then naked. Find what makes it more peaceful, exciting, uncomfortable or difficult. Then decide what is best for you at this time. Don't get dogmatic about it. Don't make it a habit. It will get easier, but keep yourself open minded about your experience. If something tells you to do something differently… listen to your intuition. When it's time to expand it even more, you'll be ready for it.
Congratulations! You are on your way.