Could you be specific as to which Canon XL? Could be an XL1, XL1s, XL2, XL-H1, or ???
The first thing I'd consider for a "filmic look" is frame rate. The XL1 and XL1s have "frame mode", which is a lousy simulation of 24p film motion, that you may or may not want to use. The XL2 and later have true 24p capability, which you'd almost definitely want to use.
Actually, yes, the XL1 does have what they call "frame mode" (you'll find it in the menu), but one clarification... it does not simulate 24p. "Frame mode" is a 30 fps progressive mode. It looks somewhat filmic, but it does not look like 24p.
That being said, if you are going to just use the XL1 as is, the "frame mode" would probably be an ok choice, as it does look a bit more cinematic than 60i... which looks very "videoy," of course.
Not to be all glass-is-half empty, but... the XL1 was a great little camera in its day, very new, cool, and innovative. But... it's day was a loooong time ago now. It is, sadly, quite a dinosaur. You're never going to get a truly filmic look out of it, but there are a few things you can do, in addition to shooting frame mode.
You could use a DoF converter and cine lenses with it. But, you're getting into real money there, and I take it that you're trying to do this on a budget with gear that you have and I'm sure you don't want to buy accessories that by themselves will cost a lot more than the camera is worth. And it wouldn't be wise to buy equipment just for any obsolete standard-def camera (unless you planned to buy, say, an XLH1 someday... which could also use it). Barring that, just shoot your project exactly like you were shooting film... not video. Frame things more like film. Use lens focal lengths more like film. Block camera moves in a filmic way. Most importantly, LIGHT as if you were lighting film, not video. I'd say lighting is the most important of that. Do NOT zoom at all, or if you have to, zoom sparingly (a real film shot with cine primes would never have any zooms). Block camera shots with longer focal lengths to give the appearance of a shallower depth of field.
Rather than "Frame mode," you can also use it in 60i and use post production software (such as Magic Bullet) to simulate 24fps with a 3:2 pulldown.
In short, you're never going to get anything out of that camera as-is that REALLY looks like film... but it will still do a nice job and many good projects have been shot with it in the past.
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Thanks for all the great advise I will put it to use and I am going to get a DOF adapter for my XL1 and see how much of a difference it would make my film and Im looking to move up to the XLH1 soon I got the XL1 because a friend of mine said that it was a good camera for starters and very cheap. But im saving to get a better camera soon.