When it comes to role models in my life, the one at the top of my list is my dad. Not only is he a fantastic dad and overall generous human being, he is also my guiding light in my entrepreneurial career.

My dad started his humble vacuum cleaner and sewing machine repair business 30 years ago, after accepting early retirement after the company he worked for his entire career was acquired.

Well into his eighties now, he is still tinkering with vacuums and sewing machines, though he is nowhere near as busy as he was -- due mostly to the fact that his industry has died with the help of inexpensive machines.

As humble a business as his was, it had a lasting and positive impact on me and my entrepreneurial career. In my business, as in my life, when I find myself in a conundrum, I often default to asking, "What would my dad do?" Inevitably, I will recall one of these lessons:

Quit complaining. My dad taught me that complaining solves nothing and, in fact, exacerbates any and all tough situations. As one of the most optimistic people you could meet, he never complains or has an ill word to speak about anyone. He stays neutral in political conversations, rarely talks about bad news, and always has a generous helping of affection for everyone. As I get older and, unfortunately, more crotchety myself, he is always quick to turn all conversations to a more productive tone.

Appreciate what you have. Fixing vacuums and sewing machines for a living never made anyone rich, but my dad always seemed to provide enough to make his family happy. More importantly, he instilled lessons of humility and encouraged us to recognize and appreciate that we were fortunate to have what we had.

Control your message. My dad was a closet marketing expert. He was profoundly good at negotiating because he could turn negative concerns into positive attributes almost magically.

One example of his messaging prowess is how he handled my birthday, which falls on Christmas Eve. Every time I tell someone about my birthday, I always hear an empathetic groan followed by, "I'm sorry to hear that", as by most accounts, this is a very unlucky time of the year to be born. When I was young, however, my dad always reinforced how "lucky" I was to have a birthday so near Christmas, so I never thought twice about it.

Prioritize those you love. As busy as he was with his business, my dad always made time for his family. He was also very smart, often encouraging my brother and I to help him with household chores, something he had a way of making fun.

As we got older, he would often tell us that there is always time to make up work, but you cannot make up for lost time with your family.

Give more than you take. My dad was incredibly generous, especially when it came to his business. On numerous occasions, I would witness customers visiting his shop for a simple problem, which he would in turn provide his service for no charge.

Even though I was young, I would question how he could give stuff away for free. He would simply say that little displays of kindness go much further than nickel-and-diming people. Although he is not nearly as busy these days, most of his customers are people he has known and done business with for years.

Wake up early. I rarely remember a time when I woke up before my dad. He emphasized the old saying, "The early bird gets the worm." I later figured out that he would often do chores around the house in the mornings so he could make time for his kids after work and on weekends.

Foster close relationships. My dad is not extroverted and has only a few friends, but the friends he does have are people he has known for years. He taught us that friends come and go, but when you find good ones, you should hold onto them and not take them for granted. They require just as much attention and respect as your family.

Exercise your body and your mind. My dad has long been someone who eats healthy, exercises regularly, and reads to keep his mind sharp. The benefits of regularly taking care of his body and mind, starting at an early age, are undoubtedly clear. Like him, I too hope to act -- and be able to act -- 20 years younger well into my later years.

My dad and I share a similar entrepreneurial background. We both left established corporate jobs to start a business. Neither of us had any experience in the industries or businesses we started, and for the most part, we both have had a bit of success in our entrepreneurial endeavors.

What makes my dad so much more of a success story is that while I had him to lean on through my trials and tribulations, he achieved all he did completely on his own.

This, in my mind, makes his courage and accomplishments much more admirable.

What lessons did you dad teach you about business? Please share with others in the comments section below.