Hmm, I guess it really depends on personal preference. I use both, but it depends on how I want others to read it. Typically when I write from a limited first person viewpoint, I will use present tense, acting as if my character is experiencing things the same time the reader is. When writing in 3rd person (limited or omniscient) I fall into a past tense.
I've noticed that many writers will use past tense, as if 'retelling' a story that has already occurred. I don't think this is wrong, it really depends on the presentation of the story.
I've rather enjoyed using 1st person present tense, as I feel it invokes a more intense and personal experience. Play around and see what suits your needs with the story best; it's different for each one!
M. Hendrix
I think it depends partially on the type of story you're writing. Personally, I think you should write the tense that you prefer reading, although there are times when other tenses do work better. The only thing with present tense is that it's not a natural way of speaking, so it's harder to get it right the whole way through.
I've written a few stories in present tense, but was only happy enough with one to publish it. I quite like that one, and, because of the contents, it worked pretty well, I think. As you say, it's good to experiment, because it definitely improves writing style and skill, and it also helps you to discover exactly what you prefer, from experience and not from other people's opinions.
As far as confusing tenses with regards to references to the past, that's not so hard once you figure out how. It works exactly the same way as normal tense, except that you wouldn't have words like 'had' when writing in present tense, but would use 'was' instead (when referring to the past).