I mess around quite a bit on slide but I don't normally tune my guitars to open tunings. I usually just drop down to D and us the slide on the top 3 strings for rhythm type stuff... and do the lead with my fingers on the lower strings.
Just like playing normal 6 strings, there are those certain techniques that you have to get use to... Such as muting with your pinky and ring fingers behind the slide to minimize noise when you don't want it when you're coming off the strings or going onto the strings. If you really want to appreciate the tone of slide guitar go to a local shop and pick up a resonator. Those things are fun to play slide on!