In memory of my mother. Much of this is by rights her work.
Be honest with yourself. Some ways of doing this include sitting alone in deep contemplation, practicing dealing with unpleasant truths by dragging them out into the open regardless of personal comfort, and finding out the hard way that you don't like a given person, place, thing, or situation. This is the most important thing in any spirituality because if you can't be honest with yourself you'll be in a prison of your own making.
Strive to be good. As good, positive, and kind as you can possibly be. Every minute of every day! It's impossible to control the world, but you can (usually) control your mind. And if you can do that, then you can do anything, and be anything.
To assist you in the above, you might want to have a mantra you repeat to yourself to remind you what's important to you. Mine is "kindness." But I bet you could think of something that suits you best.
How to meditate without a focus: Set a timer for five or ten minutes. Sit comfortably in any position that works for you. You don't have to sit with your legs crossed or full lotus or whatever; in a chair is fine, as long as you keep your back straight. Close your eyes, rest your hands on your thighs, and relax as much as you can, physically. Let your mind rove wherever it wants to but keep in mind the intention to relax the mind and let it float in nothingness. Let the thoughts float by like clouds as you breathe. Remember that this is to give yourself a break from thoughts and let your mind rest. Eventually the thoughts will cease and you will feel different, but in a good way. Practice makes perfect, so try to do this at least once a day, every day. It has significant benefits. You can do this when you're stressed, during work breaks, while traveling on a bus or plane, or anytime.
How to meditate with a focus: Same deal as above, but focus intently on something, such as a positive ideal like peace.
It is recommended to meditate outside every day possible. Be sure you wear bug spray, but other than that, it's probably the best way to chill out while getting in touch with nature. You might want to try this: find a spot out there you really like and sit with your back straight in any position you can manage. Imagine the boundary between your skin and the outside world melting. Then imagine the boundary between your inner self and the outside world melting until there is no "you" anymore. If this spooks you, you can always pray to a higher power for protection as you do this or ask your guardian angel to protect you. Guardian angels exist for everyone regardless of religion. They're a thing.
Guided meditation: This can be basically anything that you guide your mind through. It is best to keep it simple. You can write your own guided meditations for anything at all; the only limit is your imagination. Here is an example: In the same position as above, imagine that you are on a beach, listening to waves.
Meditation while in action: Use meditation with or without a focus as you go about a simple task, such as washing the dishes or taking a walk. Actually, it is possible to do this so often that your life becomes more clear-cut and you generally feel less hazy about your reasons for doing things. This cultivates your awareness.
Creating a shrine or sacred area: Quick! What's sacred or super important to you? Got it? Create an area in your living space dedicated to it. Done.
Once you have defined what is sacred to you, then logically you should defend it. If it's nature, become a treehugging nutcase like me. If it's something else, do what you must, but don't hurt anybody.
My fiance is from Texas and says that in Texas you are raised to do someone a good turn every day. He says that he tries to do something good for someone three times a day: at work, at home, and on the road.
Journaling: At the end of each day write down anything you want to remember. Every month or so, go over the journal to monitor your way of thinking and day-to-day conditions. Then you'll see if you can change your thought patterns for the better, or change your habits or life in some way.
Make a list of things that make you feel right at home and happy. Then whenever you're lost, look at the list and try to bring more of those things into your life. You can also make this into an art project or collage.
How to run an experiment to see if anything spiritual is even remotely based in truth: Find something to prove or disprove to yourself. Maybe a guess about something in the universe or something other people devoutly believe in. Once you've picked the subject of your experiment, spend time studying and analyzing it. If it's safe, interact with it, reach out to it, try to observe it, play around with it. Then run an experiment using the Scientific Method. If you're lucky a pattern will emerge. If you're not, well, tough.
The Scientific Method:
Simplified, the Scientific Method goes like this: Make an observation, ask a question, form a hypothesis (testable explanation), make a prediction based on the hypothesis, test the prediction, iterate iterate iterate iterate iterate iterate (use the results to make new hypotheses and predictions and repeat the entire process over and over again). Here is another method of explaining it: ScienceBuddies
Learn logic. Resources: A brief introduction to logic Get acquainted with deductive and inductive reasoning Logical reasoning questions and answers Wikipedia List of Logical Fallacies A textbook of logic Mathematics in 10 Lessons Alice in Wonderland
Other nondenominational spiritual practices anyone can do