All good suggestions. I go to our middle school's "Bulldog Mile" which has the top 10 milers from each grade. Their classmates come out to cheer them on. I hand out flyers that emphasize all the fun stuff of being on cross country (meeting kids at the high school before the school year starts is a big one), being on a team, getting in shape, etc. I also mention that if they can put one foot in front of the other, they can run cross country! A lot of kids think they have to be already good before they come out. I try to dispel this idea.
I also have a meeting at the middle school and tell kids that they don't have to be great athletes to run cross country. Of course, I'd like to get great athletes, but honestly, some of the kids who aren't great athletes turn into OK distance runners. I have a freshman boy this year who didn't even make our middle school's Bulldog mile, but heard my cross country pep talk, came out, trained well starting last summer, and has run 10:05 in the 3200 this year so far.
If your school doesn't have the equivalent "Bulldog Mile" talk to the PE teachers and find out who does well in the mile or pacer and make a special effort to contact those kids- especially if they are kids who don't really shine in other sports.
You also need to build a great summer of pre-season training. Love the 100, 200 mile etc club idea with T shirts- think I might have to add that to our program.