If your locks are all crunchy and noisy when you turn the key like mine were, you can spray them with some silicone spray to lube them. My driver side lock was really bad, especially when unlocking it, so when I had the interior door panels off, I sprayed the lock tumblers. It hasn't given me a problem since (about a month now).
You can also use powder graphite to lube locks, which is usually available at Walmart in the auto department, and I'm sure auto parts stores. It's in a small tube, you place the end into the lock (from the outside), and give it a puff or two. Then move the key back & forth & turn it in the lock to spread it around.
Since you've got the interior panel off, you should also grease up the window tracks. I'm not sure what's recommended, but I used white lithium grease on the tracks the run horizontally under the window, white lithium spray grease on the pivoting points (where it was hard to put the other grease), and on the vertical window tracks, I sprayed silicone spray there.
Since I had the silicone spray out, I also sprayed it on my door seals after cleaning them, to freshen them up :thumbsup: But be careful with that stuff, it will discolor plastics if you get any of it on them!