Worst case scenario?  Don't sell the initial tokens at all.  Allow anyone who is interested to sign up and receive free tokens to seed the initial amount.  Make a topic on the Altcoin ANN section and make an announcement on the cryptographic mailing lists so no one can claim you didn't try to let as many people as possible know.  Let those who received the free tokens then assign their own monetary value to them and let the network's value grow organically afterwards.