1. Know exactly what you are looking for in skills, experience and DNA - people that do well in start-ups have a different mix than those that belong in mature/large co's.
2. Look everywhere- online, social networks, job boards, conferences, referrals, linkedin, etc.
3. Write job ads that stand out vs. typical list of job requirements (treat candidates like customer prospects and write your job ads with compelling copy)
4. Offer careers, above market comp (not necessarily cash), chance to work with a great company/management/team.
5. Never stop recruiting.

Good luck!