Spot on. Only thing I would add is

11. Invoice frequently, on schedule, like clockwork. Drop anyone who doesn't pay on time.

12. If you are doing them any "favours" for any reason (discounts, work you might do but don't charge for), put it on the invoice.

I didn't understand your point 12 at first but I think you mean that you should always write down in the invoice what you did for free so that the client is always in the loop about all the work you do (whether you bill for it or not). That makes a ton of sense. Easy for humble people to not think of. Better to keep everything in the open.

You can do twice as much work as you bill for, but if you don't somehow show the client it's all for nothing. You get no goodwill, which is typically what businesses are looking for when they do free work. I try to always show any extra work done and what it would have cost on the invoice.

I'm not the parent poster, but I have always found that, to an extent, the more detail you put on the invoice, the better. There are some people who seem absolutely compelled to say "but you only did x" if they only see one thing on the invoice, no matter how involved that one thing is. Next piece of advice is to fire anyone who questions the price (at least more than once maybe...)

Put what you did with a price attached. On a separate line put a discount for that much money (with reason for discount if you want). So instead of "what you did for free" it's quantified $X discount.

Which is another way of saying "Don't do anything for free" or "There's a big difference between $1 and $0."

If there's a line item you're charging them, and then a credit, it's apparent to everyone that your work has value. If it's just missing... then the value can be forgotten much more easily.

You're still doing it for free. But at least it's properly accounted for.

Yeah, it's about setting and managing expectations. Small favours can help build relationships, discounts can help close a deal, and so on. Less relevant for larger clients, but may be necessary when working with smaller clients.

Writing it down can be the difference between the client thinking "I understand what you did there is a one-off favour and I appreciate it", versus the client taking it for granted as something normal and always expecting it in the future at no cost / discounted cost.

Yes, you don't negotiate from a discount. By putting this on there you're showing that they are already getting a discount; when they ask for more you'll be able to highlight the stuff you've already done for free.

> Invoice frequently, on schedule, like clockwork. Drop anyone who doesn't pay on time.

THIS. We bill monthly but sometimes I'll hold a project that isn't complete. BIG MISTAKE and my wife who's the CFO reminds my everytime she "finds" time logged from 6 months ago that was never billed. I'm better now, but the business world works on a schedule, your billing should too!

I will admit it took me an embarrassingly long time to learn this lesson and become disciplined enough to do it.

But it really is better for everyone involved, clients don't like late or unpredictable invoices either!

Detaching emotion from billing is important. Sometimes I would hesitate to bill because of a recent bug or miscommunication. Hug error on my part. Everyone gets billed every month no matter that status of your project. I also will bill some clients EARLY if I'm concerned, they won't pay or will balk.

Let's say I write some JS widgets and want to reuse them on multiple sites. What kind of license do you recommend? It's not open source, but is there a good boilerplate for this kind of thing? Or a question-tree like GitHub's pick an open source license, but for non-open source?

Don't mess with licenses. Just keep the copyright with the code in the project. They have your permission to use the widget (implied license, basically), so they're in the clear, but they won't be able to distribute it beyond what you've allowed, legally.

Not an expert, but going back to basics you only license things you own. So if they will retain the IP you don't license anything.

Pretty much all of this.