Whenever I try to create a public match so I can play with an Xbox live friend, public players never join. What am I doing wrong?
1) Make sure it's public!
2) Leave everything possible random. Unless there's some sort of weekend challenge, in which case pick the minimum requirements to fulfill the challenge (so when we had the Kill Brute challenge, Silver, Reaper would have been good settings).
3) Patience! Seriously, go check out your powers and/or weapons for a bit. Or play a bit of Tiny Tower on your phone. It usually takes at least a minute or two for people to show up!
4) Timing. If you're trying to play at 10am, probably everyone will be at work or school. This should change a in a few months when school lets out for the summer. In the meantime, trying to start games after 5pm is probably your best bet!
5) Murphy's Law: The BEST way to get a full party is for your friend to log and you send him an invite. I can't tell you how many times I've had an empty room, seen a friend log in, send an invite, and then have the room fill between the time he joins my Xbox live party and navigates through the multiplayer menus.
6) If you're playing on PS3, or PC there may not be as many people, and good times to get games may be different.