CCAvenue

Legal: Get Everything In Writing
There's no such thing as true loyalty in business; instead, it's all about mutual interests at a given time. Clich's aside, businesses have a mob mentality with employees and employees in turn have a mercenary outlook towards their employer. As such, when you decide to leave a company and start your own business: get everything in writing. When you announce your resignation and tell folks you want to start a business, they tend to be supportive. But once they see you actually launch it, their jealousy and pettiness comes to light.

I left with verbal promises that "we look forward to investing in your company" but was greeted with a lawsuit alleging I violated my non-compete (which I wasn't). Thankfully I had other documents in writing and managed to win.

Financing
"And bad mistakes, I've made a few"
We are the Champions, Queen

You would think that every company under the sun has just raised millions in series A and is about to "change the world". Reality is most companies don't fit the VC's profile to begin with, let alone actually raise capital.
I've already discussed how I've bootstrapped my company initially because I didn't have to raise capital, then because I tried to convince myself that I didn't want to only to refuse to accept what came with the territory when I came around, then simply not playing the game properly when the money was there.

So while as much as I love being master of my own domain, I also want to stress that VCs tend to get most excited about a company early on when their imagination can run wild about a company's future hockey stick growth curve prospects (no matter how foolish that may be).

Corporate Development
"The Only Rule Is That There Are No Rules"

Negotiating is tricky when you're buying a $10 shirt at a flea market, but when you're trying to sell a company for $10 million or $1 billion, it kind of gets trickier. Ultimately, however, companies are bought, not sold (I heard that from LUMA Partners' Terence Kawaja, but that saying is as old as M&A).

Sometimes you need to sit back and wait for someone else to make the first offer, other times it's best to throw out a figure to anchor the range. Sometimes it's best to strike a commercial deal before holding out for the exit, other times giving away the milk (be it for free or not) ensures that no one pays for the cow.

Sometimes you need to run a process with as many bidders possible to create tension, other times that will alienate an interested party who's a great fit and really wants to buy you.

HR: Not Hiring Support
The best entrepreneurs and executives realize what their weaknesses are and hire or partner accordingly. However, sometimes it's helpful to reinforce the functions where your strengths lie, too. When the company is small it's easy for you to do it all as the jack of all trades, but when the company grows you'll suddenly find yourselves stretched too thin. So while I'm not recommending you to have an entourage everywhere you go, don't think that "bench support" only refers to staff in areas you're weak at.