Recruit self-motivated, responsible students.
Talent is of no value if a person does not possess the passion or work ethic for research. Do not underestimate the potential of a single irresponsible, disrespectful, intolerant or lazy individual to sap the morale and cohesion of your entire research group. Screen applicants carefully with respect to goals, motivation and expectations. Check references whenever possible. Have members of your group meet with prospective team members, and listen to their feedback.
Invite potential outside evaluators to be seminar speakers.
The opportunity to meet you, interact with your lab group and hear your ideas will enable potential external evaluators to write more informed and dynamic letters of evaluation than someone who is working from your curriculum vitae. These seminar visits also will provide your department head and tenure chairs a chance to assess the suitability of these potential evaluators.
Think of your research program as an investment portfolio.
If you put all your assets into one high-risk venture, you may reap great rewards, but you may also crash and burn. Develop a diversified portfolio. In addition to your main, bread-and-butter effort, establish a low-risk project (or two) that is likely to produce useful, if unspectacular, publications even during off years. Look for opportunities to spin off a methods paper in addition to a research manuscript. Talented undergraduates represent an excellent source of labor for carrying out low-risk projects as well as for exploring novel, high-risk ideas.
Identify the service and teaching assignments you find most rewarding and seek them out. If you wait passively, you will end up with the leftovers. Getting your service credentials established early also leaves you with one less thing to worry about later in the tenure process. Saying yes now makes it much easier to say no somewhere down the line.