Leave the DSLR at home (note, I did not say get rid of it--I have a DSLR, too), and go shoot. Once you've worked with your camera's meter and/or a handheld meter, done some reading about the "rules", and gone through some of the learning curve, shooting film will start to come naturally. And don't worry too much about wasting film or missing shots, there's no way you can capture everything you see (although I've seen plenty of digital shooters try). (Garry Winogrand is supposed to have said, when someone asked him about 'missing' shots, "if I'm not photographing, there are no photographs to miss".*)
And unless you're a professional and on the hook to deliver something, I wouldn't worry too much about having driven somewhere for photographic purposes and made a technical error. I've done such things as hike in to a place I wanted to shoot with my P67 and tripod, shoot a roll of what I thought was 220 film, then realize that I'd left my 120/220 switch set to 220 and shot at least 10 shots on nothing but the back plate. It was still a great day (once I reloaded and fixed that little problem). If you're still learning, and especially if you're an amateur, you have to feel free not to be the best, at least at first.
I do like the suggestion of picking a film speed and sticking with it--I think I shot nothing but Tri-X (400) all through high school. That eliminates another issue I've had, which is forgetting to reset the ISO when I change film. (This will be easier to do as Kodak axes everything but Tri-X anyway.)
*Any Winogrand fans, feel free to correct me about this.