Steve and I did submit on reddit for the first few weeks after launch under multiple usernames (there were no comments or self-posts, so it was just link submissions).

We also asked friends & family to use the site, and a few of them did, but we had to go beyond our limited personal network to ensure new and interesting links on the front page every morning. Fortunately, we only had to do it for a few weeks and there was enough momentum after that for us to just routinely post under our proper account names.