More than a million recent college grads will enter the U.S. workforce in the coming months, according to the National Association of Colleges and Employers, and they will bring an infusion of fresh ideas, energy and creativity.

Yet more than 30 percent of employees leave their jobs within the first six months, according to a recent study by BambooHR.

Related: Onboarding Essentials: What Really Matters to New Employees (Infographic)

Startups often don’t offer the comprehensive training and onboarding programs that large companies use to cut down on attrition rates. So how is it possible to ensure that those hired this summer don’t end up quitting before Thanksgiving?

Mentoring can help new hires develop key skills to accomplish their ambitious goals and build the personal relationships that anchor them to  a company.

Research done by MTV in 2011 showed that three-quarters of millennials would like to have a mentor at work. When done right, mentoring is a simple way to help a new hire become accustomed to the demands of a workplace and be more likely to succeed.

Here are five tips to ensure that new hires can take advantage of great mentoring experiences:

Related: The Problem With Hiring Millennials Is Their Age, Not Their Generation

1. Reach out informally. New hires probably like the idea of having a mentor but don’t know what's involved. Encourage a co-worker to approach the new hire, get to know the person and offer to help.

At first, conversations should focus on how things work at the company and easing the transition between college life and the workplace.

Communication and interpersonal skills should be among the initial topics, as more than 60 percent of employers feel that new job applicants lack these critical soft skills, Time reported.

Avoid the urge to make the program too formal as excessive structure can get in the way of a good experience, according to a Bloomberg Businessweek article about mentoring millennials.

Related: The 10 Unique Soft Skills Employers Desire in New Hires

2. Provide feedback. Millennials crave constant feedback -- not just annually but daily. The need for feedback is connected with their desire for self-improvement. But knowing about areas for possible improvement is only half the battle.

New hires will need regular feedback as well as a road map to guide them in improving. That’s where mentoring fits in. A mentor can offer advice about how to work on specific skills. If a new hire’s manager isn’t providing enough feedback, a mentor can provide pertinent advice.

3. Teach a new hire to be a good protégé. Assigning someone to mentor a new hire is one thing. Teaching the new employee how to make the most of the relationship is quite another.

Mentoring is a two-way relationship and protégés need to participate fully to gain the most from it. Advise these employees to take responsibility for their self-development, set clear objectives and take notes on what's been discussed so that they can act on suggestions and report back.

The most productive relationships are driven by the protégé (not the mentor), as Kathy E. Kram documented in her book Mentoring at Work: Developmental Relationships in Organizational Life

Related: 6 Keys to Developing Millennials Into Managers

4. Vary the menu. As Facebook COO Sheryl Sandberg has observed, the typical career progression today looks more like a jungle gym than a ladder. New hires need a diverse set of tools to navigate their careers. Just like one-size-fits-all training won't meet the needs of a growing team nor will generic approaches to mentoring,

Over time consider layering in one of these innovative approaches to mentoring: a personal advisory or shadow board whereby protégés work on the same challenges as top managers, trying to find their own solutions; reverse mentoring, when executives learn from millennials; speed or rotational mentoring (somewhat like speed dating), when employees learn quite a lot in 15-minute intervals.

5. Don’t assume anything. In their first jobs after college graduation, these new hires won’t know much about a company’s culture or even the industry. Assume zero knowledge and progress from there.

New hires might be afraid to ask questions that seem basic or stupid so don’t put them in that position. Avoid jargon, acronyms and references to company systems unless they are fully explained.

Since it can be difficult to see the company from the perspective of someone with no experience, consider developing a web resource (such as a wiki) that covers everything a new hire needs to know. That way, starting fresh won't be necessary each summer when the new college grads arrive.

In the ideal scenario, the new hires will contribute the lessons they’re learning from their mentors to the company's central resource so it continues to evolve along with the firm's business.

Related: Can't Afford Employee Training Programs? Think Again