If you can fit another day or even two in there, I would do it. One day is not even close to enough for Disneyland. You need, especially in the crowds to properly experience Disneyland itself, nevermind DCA.
That said, here's what to do. Be inside the park as close to the right side on the end of Main Street as you can at rope drop for Nemo. Head there first thing in the morning and resist the temptation to do anything else. If you do something else before Nemo, you're likely looking at least a 1 hour wait for Nemo. After Nemo, do Matterhorn and Space. From there I would head over to Indy and pick up a fastpass(note that if you fastpass Space, you may have a longer window to get the Indy fastpass, so if the standby for Space is under 30 minutes, I wouldn't use fastpass).
Now, whatever you do, do not skip POTC. Disneyland's (the original POTC) is nearly twice as long and far superior to the one in the MK.
I also recommend doing Fantasyland after about 10:30pm. Fantasyland in Disneyland has a radically different feel from the one in WDW. The show buildings are beautifully themed both to Sleeping Beauty Castle and the location of the story itself. The lines are much shorter and you can experience the unique Fantasyland attractions that MK does not have(Pinocchio, Alice in Wonderland, Storybookland & Mr. Toad) with much shorter lines than in the middle of the day. If possible, do Peter Pan as well since the Disneyland version is a little bit better.
It's also fun to walk around ToonTown. Roger Rabbit's Cartoon Spin is worth doing with either a fastpass or a short wait, and ToonTown in Disneyland is much better themed than the Fair in Florida. You don't need to spend a lot of time there, but it's fun.
As for DCA, it's a tough call. Aladdin is a great show, especially to beat the afternoon heat, but with only one day I hesitate to recommend spending time in DCA especially since WDW features Tower of Terror, Soarin' and a similar roller coaster albeit with a vastly superior theme(Rock N Roller Coaster over Screamin'). Monsters, Inc. is also a fun little ride.
As for Toy Story Midway Mania, the question becomes when your next trip to WDW is since the ride itself is virtually identical. The theme is better in DCA since the ride was themed for a midway and then cloned for DHS.
I also think the fireworks at Disneyland are a must see, from somewhere in the hub.